There is two ways;
Try to change the diffuse and the uv texture
Put the costume in blender, put edit mode, if you see a dark part the body has a wrong vertex
Rachel as cassie cage endurance, thanks to @synce for the idea
i couldn't fix the neck problem, i do it with one of her costumes and i don't know why that issue appears
https://mega.nz/#!cNA0BK7L!bK7QJS8Et99qTHSkwLcK-cAiAGXHmxreCDobQfxgZ9Q
I make a test, the problem is his bone, so you need to change the hayabusa's bone into him, with bone tool
The problem is that muramasa body has a T pose, you need to scale, move all the normal bone
I do in my legacy pack the helena opera dress, i don't know why the costume has some problems with the texture... also in doa5lr noone girl has a close skirt (like helena opera dress)
I do a pack, unfortunately you need to download all the pack if you want ayane's costume
https://mega.nz/#!wV5zhTZJ!BZpr5bzL-F0xRi9jRhwoT4KWU_pBIb2l4gRNOha-K24