Can someone teach me how to model swap

[Bond of Blood]

I want to swap my ramarl with jill from resident evil and I want to combine the devil wing and devil tail skin mag I really don't get why that isn't a thing already. If someone can help out with this I can paypal you money.

 

[SirLagsAlot]

Theres a few resident evil skins on here (not a model swap)

Univers-PS - List of Skins : RAmarl

universps.online.fr