If everything is still tight (key in head) and you say that most all your bolts in you bike were orvertorqued,AND you are ABSOLUTELY POSITIVE that you are turning in the correct direction then we go to a cheater.Find a pipe or crescent wrench to slip over end of wrench to gain a longer handle to twist that little bugger out.There is a risk that something could break but its nothing an electric drill and a good bit wouldn't take care of. It wouldn't hurt to apply a little liq,wrench to threads anyway. Regards, Frank