Error Creating Character- Please help.

Does anyone know how to get the WoD models to work on WoTLK? I like them much more than the old ones and wouldn't mind having to do a lot just to get it to work. I just need to know what needs to be done for it. I've googled to see if there's anything that could help me but only found one video on it but it was on a different Server and said it doesn't apply to other servers. I would really love a fix to this if someone could explain or give me a link to something that would help me. Thank you.