[Tim Ayers]

Yep. Heat is the only thing that does it at this point. If they so tight that they aren't coming out, no chemical known to man is going to creep in there. Use a torch, or my preferred method, induction heater tool, to get the base of the stud dull cherry red. Let them cool and then try to remove.

Sometimes tightening first, just slightly, helps it to back out when you apply opposite force. The idea is breaks the bond.

This job takes a bit of feel for it. Once you do a few, you'll know what I mean. Don't go in with brute force. Gentle pull slowly increasing force. You'll feel and sometimes hear if it's going to go or not. If not, reheat. One block, I had to do two heat cycles to get them out.