first off, i would suggest that anyone attempting to remount bindings should just bring it to a shop, it will save you time and anger.
now, heres what to do about that striped screw. i have 2 solutions that work great. first one. go to sears and get a ez out bit set. they are shaped to bite into any surface and then to twist that surface out. they work great.
My next solution is to go and get a dremal tool. take a cutting bit, and cut a large slot in the screw head. if you do it right, it will look like a flathead screw. then just take a flat head screwdriver and screw it out.
eather way works, but jst save yourself time and give it to a shop to do.