Well, simply a vanity item for the head would be easiest - from what I can tell it's just one image repeated a few times unless you want to add a 20-frame (or 10-frame or 5-frame or 4-frame whatever) animation to it. If you messaged me the sprite for the head, I could put it together pretty easy I think - just lemme know what head vanity you'd want me to replace.
For the body and legs, however.... Simply put, it's very complicated and I don't actually understand how the sheet works yet. So if you wanted to make that happen, it would take quite a bit of effort, but I can try - just let me know.