by edit, you mean reskin? if so, 2004, just open the folder containing the model and adjust the tga textures. In 2006 you need to open the item for editing in cmp and then open the tga's (open with external app) through that (I think) dont use 2006 much. In either case if you want to release the adjusted models you will need to request permission from the original author.
cheers
pete
