If you're confused about how to integrate the outfit to the avatar, I posted a pretty lengthy tutorial in the comment section of this product: https://dein-ra.itch.io/jwmasccaninelatexoutfit which is also a latex outfit, but for a different avatar.
The TL:DR is essentially mixing the body latex textures with the avatars body textures using PS/GIMP, while the meshes are assigned to the avatars own Armature in Blender before FBX exporting.