My 1991 Camaro RS, it's tensioner for the serpentine belt, the pulley on the tensioner in specific, the bolt that holds it in snapped off inside where I can't get a grip on it to back it out of there. What tool or trick could I use to back the screw out of the tensioner, it's snapped off inside to where I can just pull the pulley off the car while the belt is on tight if I pulled hard enough