Busted Phillips Screws

one of the lugs on my speakers came loose , so I used a power screw driver to remove the Phillips screws holding the plate in the back. 3 out of the six screws came out fine. The other three had the indentaions smashed, now I am stuck with three phillips screws that I can get out. Will seek the advice of someone more mechanically inclined then myself, but any advice is appreciated. My thought is to take a drill and destroy the screws completely. However I wont do anything until I consult with a few friends. THX