I'm trying to remove the heatsink from a Mac Pro 2009, 2.66 quad core, after upgrading from 4.1 to 5.1. The intention is to fit a X5677 processor. The bolt in question is the single one on the left looking at the motherboard, not the four around the CPU itself. The stripped head is a problem and I can't see a solution. I asked an engineer friend and he said the only way was to drill out the head. We talked about using a #3 allen/hex key with superglue on the end, but if it's a captive bolt I may end up in even more trouble. He suggested a 8mm drill bit, which is the diameter of the allen bolt head. I removed the motherboard from the tray to see if I could unscrew anything from underneath, but it looks like the base part of the nut is glued into the PCB. I can only trust that if it were drilled out I could then find a solution to re-attach it. I don't think it's that critical, since it's the 4 bolts around the CPU that hold the heatsink tight to the processor. Can anyone suggest a solution for this?