I have narrowed the noise coming from my car to the belt that runs the A/C. I looked up how to replace the belt and I need to loosen the pulley which keeps the belt tight as the fan runs the belt, etc. But my problem is that after an hour and a half of trying to loosen the bolt which keeps the pulley pressed against the belt. does anyone know how to loosen the pulley or change the belt without loosening the pulley? I've sprayed the bolt with wd-40 and metal loosener, but nothing has worked.