Got some parts to replace a sticky-shift key, poorly-backlit, wine-spilt keyboard for the 13" MBP. Now i just need to get a tri-wing screwdriver, but I got stuck on the bottom left screw of the logic board: the small philips screw stripped. What to do? I could carve a flat head groove by continually shaving down a sliver, but what other (low-cost) options are there? Thanks. Sigh.