Install via: dragging and dropping the mod's data folder into your Skyrim data folder or install via Nexus Mod Manager or whatever.
Craft the polymorph tome at a forge for 1 gold each. You won't have to craft the other 4 skins, they come automatically.
Permanent transformation to avoid the revert crash bug.
You should probably polymorph outside of friendly settlements otherwise they'll get mad. Use the become friendly spell to safely re-enter without hostility.