Any suggestions on how to remove a firmly stuck set screw that is now stripped? Set screws are the four short screw/bolts that clamp the Rover halves to the boom. They're the ones that go into the corner of the frame tubes on Rovers of the last few years. I'm not talking about the older Rovers that had large bolts go straight through the frame.
In my case, I noticed sometime last year that 2 of the 4 were firmly stuck (presumably rusted in place), and in fact sheared off the bit on my 3-way allen wrench. Earlier this month I gave it another shot. This time did several passes of WD-40 over several days, getting both the exposed side of the bolts as well as squirting it into the frame to get the back end.
I got one of them loose, but the other has now has it's hex hole stripped. Using the proper sized bit just results in the bit clicking around, and a larger bit won't fit in the hole. Can the set screws safely be drilled out? How hard are they, are they hardened steel? Any other ideas on how to get the last one out?