drop the save into your save folder (Documents\BioWare\Dragon Age Inquisition\Save)
my inquisitor should show up under vex & be standing right in front of the very last shard. pick that bad boy up and bust in that ugly temple! no dlc installed, so it should work for everyone!
ETA: okay, a few people seem confused so let me put some more, super detailed instructions here in case you're having trouble, too: you don't have to collect the shards! i already did that! they don't show up in your inventory or anywhere else, but you DO have them! there is only one shard left, and you should be standing directly in front of it when you load the save. (i left it there instead of just picking it up too because when i sent a friend a file with ALL of them already collected, the achievement wouldn't register for her, but we tried again and it seems like if you pick up at least one of them yourself, it works. could have been an unrelated bug or just origin being origin, but better safe than sorry!) they do kind of blend in with the environment, so use the search function (v) if you need to
just picking up the final shard will not give you the achievement! the achievement is for using the shards. you do this in the temple of solasan, which you'll be standing right in front of it in the save. look around - it's pretty hard to miss! it should be to your left: a giant door with two veilfires on either side. walk up to it and you'll get an prompt to open. do that. it will take six of your shards and let you inside. once inside, there are a bunch more doors like it, each of which takes shards to open and has a few enemies inside.
once you've unlocked all of the doors and beat the enemies inside, a big door back near the entrance will open. there's a big pride demon inside and, full transparency, im pretty sure i had the rare weapons mod installed in this save, so if you don't have that, too, everybody's gonna be weak as fuck, and it MIGHT kill you, but i don't think you have to actually beat it to get the achievement. it should give it to you as soon as you enter the room, so you can just run around taking damage and letting my inquisitor die (rib scrub) until you get it!
if you get an error when trying to load the file that says something about the patch not being up to date, it's because you don't have mod manager and i do! it changes the patch number in order to install mods, so you just gotta change your patch version number to the one mod manager changed mine to.
your patch folder (probably in C:\Program Files (x86)\Origin Games\Dragon Age Inquisition\Update\Patch) should have a file titled package.mft. open it in notepad, change the version number to 13, save changes, try it again, and be sure to jump back in and change the number back to what it was (most likely 12) before editing so your future saves won't have the wrong patch number!