Here I just wanted to share what little i know about armor mods.
This post is for those of you like me who don't know anything about mods but still want to use them.
if you are someone who understands about mods then please skip reading this or if you can please correct it because this will be a long read.

So to use the armor mod we need to replace the armor parts file that we will use with the mod version of the armor parts file. the problem is that 2 of my favorite mods (2B Nier from asasasasasbc, and Ranni skin from ApolloHoo) use the same armor parts (Astrologer Set), so I can't use them at the same time.

But there is something that is quite easy to overcome it, by changing the file name of the mod version of the armor parts file to another ID.
To do that, there is a few points that you should know first

1. Need to know the ID of the part to be replaced, and I looked on this forum but no one listed the full version. 
    Update : thanks to Lemuroza, there is a database of parts ID on github which is more than I already know, please go to this Link to check it for reference.

2. You need to know the texture of the armor that you are going to replace, for example here I use mod 2B which replaces the Astrologer set (robe texture), when I try to change it to ID Knights Armor the result is a strange appearance (see picture) like that. including the gloves, the hands render doesn't look right, but when I change them to ID parts "Perfurmer Gloves" the 2B hand texture looks normal. (My guess is that this is due to the structure type of the item being replaced, Astrologer gloves and Perfurmer Gloves have a texture that looks similar, different from the iron/armor texture of Knights Armor). So do your research first by checking the type of armor before replacing it so it doesn't look weird.

3. Also the armor parts file usually has two versions, male and female. I'ts depend on the body type which one you'll be wear.

4. You must understand that enemies who use the same armor as the one you change will look according to the mod. for example, if you change mod 2B from astrologer set to Blaidd's set, then Blaidd will look like 2B. so it is highly recommended to change the mod to an armor set that is not used by the enemy.
Based on IfritXDS post, the enemy/npc using the same armor mod happens because the parts ID with "_l" file being replaced, so you may don't need to replace the  "_l" ones. for example am_m_1250.partsbnd and am_m_1250_l.partsbnd. just replace the first one.


as a reference, here I include the parts that I replaced.
1. Ranni skin for Tarnished still uses the same parts, Astrologer set & Marionette Soldier Birdhelm because I used Ranni's Spirit Ash Summon mod too so I didn't change this.

2. 2B Nier Set = from Astrologer set (1250) -> Confessor set (1400) & Perfurmer Gloves (AM_M_1130). for some reason somehow even though the Confessor Gloves and Astrologer Gloves are of the same type but when I change they give rise to a strange appearance, so the same type is not enough, the texture must be the same as well.

3. I changed the Shudad Armor from BDO  from Gelmir Knight set (2380) to Knight Set (1570), no problem.



Below is the ID Parts that I know, its just a few. You can use the link above to the github that had more than these.

Astrologer Set

Knight Armor Set
hd_m_1570.partsbnd         Knight Helmet
hd_m_1570_l.partsbnd       Knight Helmet
bd_m_1570.partsbnd          Knight Armor Male
bd_m_1570_l.partsbnd       Knight Armor Male
am_m_1570.partsbnd         Knight Gloves
am_m_1570_l.partsbnd      Knight Gloves
lg_m_1570.partsbnd  Knight Trousers
lg_m_1570_l.partsbnd        Knight Trousers

Carian Knight Armor
hd_m_1500.partsbnd         Carian Knight Helm 
hd_m_1500_l.partsbnd      Carian Knight Helm 
bd_m_1501.partsbnd         Carian Knight Armor Male
bd_m_1501_l.partsbnd      Carian Knight Armor Male
am_m_1500.partsbnd        Carian Knight Gauntlets
am_m_1500_l.partsbnd     Carian Knight Gauntlets
lg_m_1500.partsbnd          Carian Knight Greaves

Marionette Helmet 
hd_m_2180.partsbnd          Marionette Soldier Birdhelm
hd_m_2180_l.partsbnd       Marionette Soldier Birdhelm

Prisoner 
hd_m_1410.partsbnd           Prisoner Iron Mask
hd_m_1410_l.partsbnd        Prisoner Iron Mask
bd_f_1410.partsbnd             Prisoner Clothing Female
bd_f_1410_l.partsbnd          Prisoner Clothing Female
bd_m_1410.partsbnd           Prisoner Clothing Male
bd_m_1410_l.partsbnd        Prisoner Clothing Male
lg_m_1410.partsbnd            Prisoner Trousers
lg_m_1410_l.partsbnd         Prisoner Trousers

Commoner’s Set (Altered)
hd_m_2141.partsbnd             Commoner's Headband (Altered)
hd_m_2141_l.partsbnd          Commoner's Headband (Altered)
bd_m_2141.partsbnd             Commoner's Garb (Altered)
bd_m_2141_l.partsbnd          Commoner's Garb (Altered)

Banished Knight Set
hd_m_1650.partsbnd           Banished Knight Helm
hd_m_1650_l.partsbnd        Banished Knight Helm
bd_m_1650.partsbnd           Banished Knight Armor
bd_m_1650_l.partsbnd        Banished Knight Armor
am_m_1650.partsbnd         Banished Knight Gauntlets
am_m_1650_l.partsbnd      Banished Knight Gauntlets
lg_m_1650.partsbnd            Banished Knight Greaves
lg_m_1650_l.partsbnd         Banished Knight Greaves

Banished Knight Set (Altered)
hd_m_1651.partsbnd          Banished Knight Helm (Altered)
hd_m_1651_l.partsbnd        Banished Knight Helm (Altered)
bd_m_1651.partsbnd           Banished Knight Armor (Altered)
bd_m_1651_l.partsbnd        Banished Knight Armor (Altered)

Night Maiden
hd_m_2630.partsbnd           Night Maiden Twin Crown
hd_m_2630_l.partsbnd        Night Maiden Twin Crown
bd_f_2630.partsbnd             Night Maiden Armor Female
bd_f_2630_l.partsbnd          Night Maiden Armor Female
bd_m_2630.partsbnd           Night Maiden Armor Male 
bd_m_2630_l.partsbnd        Night Maiden Armor Male

Nox Monk Female Set
hd_f_1750.partsbnd            Nox Monk Hood
hd_f_1750_l.partsbnd         Nox Monk Hood
bd_f_1750.partsbnd            Nox Monk Armor
bd_f_1750_l.partsbnd         Nox Monk Armor
lg_f_1750.partsbnd             Nox Monk Greaves
lg_f_1750_l.partsbnd          Nox Monk Greaves

Nox Monk Male Set
hd_m_1750.partsbnd          Nox Monk Hood
hd_m_1750_l.partsbnd       Nox Monk Hood
bd_m_1750.partsbnd          Nox Monk Armor
bd_m_1750_l.partsbnd       Nox Monk Armor
am_m_1750.partsbnd         Nox Monk Bracelets
am_m_1750_l.partsbnd      Nox Monk Bracelets
lg_m_1750.partsbnd            Nox Monk Greaves
lg_m_1750_l.partsbnd         Nox Monk Greaves

Fire Monk Set
hd_m_1820.partsbnd            Fire Monk Hood
hd_m_1820_l.partsbnd Fire Monk Hood
bd_m_1820.partsbnd             Fire Monk Armor
bd_m_1820_l.partsbnd Fire Monk Armor
am_m_1820.partsbnd            Fire Monk Gauntlets
am_m_1820_l.partsbndFire Monk Gauntlets
lg_m_1820.partsbnd               Fire Monk Greaves
lg_m_1820_l.partsbnd            Fire Monk Greaves

Hoslow Armor
hd_m_1270.partsbnd          Hoslow Helmet
hd_m_1270_l.partsbnd       Hoslow Helmet
bd_m_1270.partsbnd          Hoslow Armor
bd_m_1270_l.partsbnd       Hoslow Armor
am_m_1270.partsbnd         Hoslow Gauntlets
am_m_1270_l.partsbnd      Hoslow Gauntlets
lg_m_1270.partsbnd            Hoslow Greaves
lg_m_1270_l.partsbnd         Hoslow Greaves

Raptor’s Set
hd_m_1450.partsbnd            Skeletal Mask
hd_m_1450_l.partsbndSkeletal Mask
bd_m_1450.partsbnd            Raptor’s Black Feather
bd_m_1450_l.partsbndRaptor’s Black Feather
am_m_1450.partsbnd           Bandit Manchettes
am_m_1450_l.partsbnd        Bandit Manchettes
lg_m_1450.partsbnd              Bandit Boots
lg_m_1450_l.partsbnd           Bandit Boots

Black Knife Set
hd_m_1610.partsbndBlack Knife Hood
hd_m_1610_l.partsbnd               Black Knife Hood
bd_m_1610.partsbnd                  Black Knife Armor
bd_m_1610_l.partsbnd               Black Knife Armor
am_m_1610.partsbnd                 Black Knife Gauntlets
am_m_1610_l.partsbnd              Black Knife Gauntlets
lg_m_1610.partsbnd                    Black Knife Greaves
lg_m_1610_l.partsbnd                 Black Knife Greaves

Blaidd Armor Set
hd_m_1600.partsbnd           Blaidd's Wolf Mask
hd_m_1600_l.partsbnd        Blaidd's Wolf Mask 
bd_m_1600.partsbnd           Blaidd's Armor
bd_m_1600_l.partsbnd        Blaidd's Armor 
am_m_1600.partsbnd          Blaidd's Gauntlets
am_m_1600_l.partsbnd       Blaidd's Gauntlets 
lg_m_1600.partsbnd             Blaidd's Greaves
lg_m_1600_l.partsbnd          Blaidd's Greaves

Raging Wolf 
hd_m_1350.partsbndRaging Wolf Helm
hd_m_1350_l.partsbnd      Raging Wolf Helm
am_m_1350.partsbnd                 Raging Wolf Gauntlets 
am_m_1350_l.partsbnd     Raging Wolf Gauntlets 
bd_m_1350.partsbndRaging Wolf Armor 
bd_m_1350_l.partsbnd      Raging Wolf Armor 
lg_m_1350.partsbnd                   Raging Wolf Greaves 
lg_m_1350_l.partsbnd                Raging Wolf Greaves 

Bull Goat set
hd_m_1180.partsbnd            Bull Goat Helm
hd_m_1180_l.partsbndBull Goat Helm
bd_m_1180.partsbnd            Bull Goat Armor
bd_m_1180_l.partsbndBull Goat Armor
am_m_1180.partsbnd           Bull Goat Gauntlets
am_m_1180_l.partsbnd        Bull Goat Gauntlets
lg_m_1180.partsbnd              Bull Goat Greaves
lg_m_1180_l.partsbnd           Bull Goat Greaves

Tree Sentinel set
hd_m_1730.partsbnd            Tree Sentinel Helmet 
hd_m_1730_l.partsbndTree Sentinel Helmet  
bd_m_1730.partsbnd            Tree Sentinel Armor
bd_m_1730_l.partsbndTree Sentinel Armor
am_m_1730.partsbnd           Tree Sentinel Gauntlets
am_m_1730_l.partsbnd        Tree Sentinel Gauntlets
lg_m_1730.partsbnd              Tree Sentinel Greaves
lg_m_1730_l.partsbnd           Tree Sentinel Greaves

Drake Knights Set
hd_m_1100.partsbnd            Drake Knight Helm
hd_m_1100_l.partsbndDrake Knight Helm
bd_m_1100.partsbnd            Drake Knight Armor Male
bd_m_1100_l.partsbndDrake Knight Armor Male
am_m_1100.partsbnd           Drake Knight Gauntlets
am_m_1100_l.partsbn           Drake Knight Gauntlets
lg_m_1100.partsbnd              Drake Knight Greaves
lg_m_1100_l.partsbnd           Drake Knight Greaves

Fur set
hd_m_1760.partsbndGreat Horned Headband
hd_m_1760_l.partsb nd     Great Horned Headband
bd_f_1760.partsbnd  Fur Raiment Female
bd_f_1760_l.partsbndFur Raiment Female
bd_m_1760.partsbndFur Raiment Male
bd_m_1760_l.partsbnd      Fur Raiment Male
lg_f_1760.partsbnd   Fur Leggings Female
lg_f_1760_l.partsbndFur Leggings Female
lg_m_1760.partsbnd                   Fur Leggings Male
lg_m_1760_l.partsbnd                Fur Leggings Male

Maliketh Set
hd_m_1620.partsbndMaliketh's Helm
hd_m_1620_l.partsbnd      Maliketh's Helm
bd_m_1620.partsbndMaliketh's Armor
bd_m_1620_l.partsbnd               Maliketh's Armor
am_m_1620.partsbn d                Maliketh's Gauntlets
am_m_1620_l.partsb nd    Maliketh's Gauntlets
lg_m_1620.partsbnd  Maliketh's Greaves
lg_m_1620_l.partsbnd                 Maliketh's Greaves

Veteran’s Set
hd_m_1660.partsbndVeteran's Helm
hd_m_1660_l.partsbnd      Veteran's Helm
bd_m_1660.partsbndVeteran's Armor
bd_m_1660_l.partsbnd               Veteran's Armor
am_m_1660.partsbnd                 Veteran's Gauntlets
am_m_1660_l.partsbnd              Veteran's Gauntlets
lg_m_1660.partsbnd  Veteran's Greaves
lg_m_1660_l.partsbnd                 Veteran's Greaves

General Radahn Set
hd_m_2010.partsbndRadahn's Redmane Helm 
hd_m_2010_l.partsbnd      Radahn's Redmane Helm
bd_m_2010.partsbndRadahn's Lion Armor
bd_m_2010_l.partsbnd      Radahn's Lion Armor
am_m_2010.partsbnd                Radahn's Gauntlets
am_m_2010_l.partsbnd              Radahn's Gauntlets
lg_m_2010.partsbnd Radahn's Greaves
lg_m_2010_l.partsbnd                Radahn's Greaves

Shaman Set
hd_m_1765.partsbndShinning Horned Headband
hd_m_1765_l.partsbnd      Shinning Horned Headband
bd_m_1765.partsbndShaman Furs Male
bd_m_1765.partsbndShaman Furs Male
lg_m_1765.partsbnd Shaman Leggings Male
lg_m_1765_l.partsbnd                 Shaman Leggings Male
bd_f_1765.partsbnd  Shaman Furs Female
bd_f_1765_l.partsbnd                 Shaman Furs Female
lg_f_1765.partsbnd   Shaman Leggings Female
lg_f_1765_l.partsbndShaman Leggings Female

Mushroom Set
hd_m_2310.partsbndMushroom Head
hd_m_2310_l.partsbnd      Mushroom Head
bd_m_2310.partsbndMushroom Body Male
bd_m_2310_l.partsbn d               Mushroom Body Male
am_m_2310.partsbn d                Mushroom Arms Male
am_m_2310_l.partsb nd             Mushroom Arms Male
lg_m_2310.partsbnd  Mushroom Legs Male
lg_m_2310_l.partsbn d                Mushroom Legs Male
bd_f_2310.partsbnd  Mushroom Body Female
bd_f_2310_l.partsbn  d               Mushroom Body Female
am_f_2310.partsbnd Mushroom Arms Female
am_f_2310_l.partsbnd                Mushroom Arms Female
lg_f_2310.partsbnd   Mushroom Legs Female
lg_f_2310_l.partsbndMushroom Legs Female

Royal Remains Set
hd_m_1310.partsbnd Royal Remains Helm
hd_m_1310_l.partsbn d      Royal Remains Helm
bd_m_1310.partsbnd Royal Remains Armor
bd_m_1310_l.partsbnd       Royal Remains Armor
am_m_1310.partsbndRoyal Remains Gauntlets
am_m_1310_l.partsbnd      Royal Remains Gauntlets
lg_m_1310.partsbnd   Royal Remains Greaves
lg_m_1310_l.partsbndRoyal Remains Greaves

Malenia’s Set
bd_f_1630.partsbnd   Malenia’s Armor Female
bd_f_1630_l.partsbndMalenia’s Armor Female
hd_m_1630.partsbnd Malenia’s Winged Helm
hd_m_1630_l.partsbnd       Malenia’s Winged Helm
bd_m_1630.partsbnd Malenia’s Armor Male
bd_m_1630_l.partsbnd       Malenia’s Armor Male
am_m_1630.partsbnd                  Malenia’s Gauntlets
am_m_1630_l.partsbnd      Malenia’s Gauntlets
lg_m_1630.partsbnd   Malenia’s Greaves
lg_m_1630_l.partsbndMalenia’s Greaves

Malenia Armor (Altered)
bd_f_1631.partsbnd   Malenia Armor Female
bd_f_1631_l.partsbndMalenia Armor Female
bd_m_1631.partsbndMalenia Armor Male
bd_m_1631_l.partsbnd       Malenia Armor Male

Lord Of Blood Robe
bd_m_2020.partsbndLord Of Blood Robe
bd_m_2020_l.partsbnd      Lord Of Blood Robe
bd_m_2021.partsbndLord Of Blood Robe (Altered)
bd_m_2021_l.partsbnd      Lord Of Blood Robe (Altered)


from the parts we can know that
hd = head/helmet
am = arms/gauntlet
bd = body/armor
lg = leg/greaves/trousers
f = female type
m = male type

I've also included a word file from the list above, feel free to download it if you want to  make it as a note.
don't forget to back up the original files before patching
and only use mods when playing offline!
have a good time!