Get a miniature butane torch and carefully heat the head. Thread locker will loose its hold when heat is applied.
I also vote easy out, chisel might be to much I think.
I also vote easy out, chisel might be to much I think.
The bolt looks like shit and reinstalling it damaged wont be good for future removal. I would use another. Structurally it might be OK but functionally its going to be pita.I can tell from your reply that you have never used such a device. It does not damage the screw if used properly.
OH impact driver.The OP asked if the impact driver damages the bolt. Your reply was "Absolutely does". Well you are wrong as countles peolple have used this tool and did not damage the bolts