Want to ask about making of "Black Desert Online Hairs" Mod

I have a plan to convert other game hair to FO4/SSE like BDO hairs mod pack I can use 3d program like blender and can import .nif to game but the part that confuse me is other game mesh come with different UV map. Which method to put my own texture or vanilla texture to all of that mesh? Can someone share me detail about this process.