how to change characters face (vertexture Question)

[arcray20]

on characters who dont have a drawn-on face.
i wanted to see if i could put some characters normal face with their 'ouch' face, like when Snake is gritting his teeth.

i thought i had to switch polygons by export then replace in brawlbox but it told me there was an error and then i clicked continue and the face was horrifyingly twisted after that. :srs:

sicne i dont want to see that again, i thought id ask for help instead. :af2: