you just need a good flat head that fits inside the screw head. i installed a different safefty on mine and that's what i did. i stood the gun up on the buttstock and pushed the flat head into the screw head. it took a couple tries, but it finally broke.
once you get it out, take that screw and throw it down the deepest cave or well you can find so that nobody ever uses it again. they're such a pain in the neck.