Uh... impossible. If the model was edited, such as with codes BigSharkZ is using, then yes. Until then... Impossible.
And even then, the codes themselves have limitations, so it could still very well be impossible... (So far, all BigSharkZ's codes have been able to do were to shrink or expand things, using other codes to make items [like Mario's moustache] disappear.)
Ifever model hacking comes to fruitition, that'd be the only way to see a true Ike-haired Marth-Roy... Until then, have to live with what we've got.~