Chewed posi screw

[Serapth]

Wasnt sure where to post this so if its in the wrong place appologies in advance..

Was just finishing off changing all my screws to hex heads on my blaze earlier when the very last one on the motor mount chewed when i tried to remove it. I cant seem to get it to budge and its now so bad the posi driver wont even fit in anymore...so how do i get it out without butchering the damn thing!