Sonic face expression help!

[Reaver Ind.]

I'm trying to have Sonic's normal face expression take over his Grin expression and his Fun expression.  Like how Shadow would usually have the Angry mouth expression over his Grin or Fun mouth expressions.  Does anybody know how to do this, and if so please help me.  Thank you.

[Akiba Red]

Export the polygon of the emotion you want and the vertices that go with it.

[DarkPikachu]

all you need to do is edit the bones...

note: since bones are common data,
they'll change the expression of every sonic model in the directory