I bought a used XR650R. Tonight while trying to remove the rear fender, I found one of the bolts just spinning with its insert, so I can't remove it. It appears to be quite stuck, I tried turning it with vice grips while pulling it out really hard, hoping the insert would have enough friction to stay put, but that didn't work. I'm looking for ideas, but I think at this point I need to cut the bolt head off and then either replace the subframe or try to do some kind of repair to it. Is there any "standard" fix out there for this problem, or do I need to cough up for a new subframe?