To get out a stuck screw, put a few drops of WD-40 around the head and let that sit for a few. Then hold the tip of your soldering iron to the head of the screw for a few and it should come out pretty easily. However, if you've already stripped the head, use your dremel with a cutoff wheel and make a slot in the head of the screw and use a flat screwdriver after applying heat and WD. Also, you could get the corally screws and replace the hex heads of the Xray with those. The Torx head screws pretty much just plain don't strip.
Tony