What tools are required to replace a serpentine belt automatic belt tensioner for a 1991 Buick Roadmaster RWD 5.0L? I know one would need a breaker bar and the socket for the mounting bolts but would one need a certain torx socket for the middle bolt on the belt tensioner? Moreover, if so what size would it be? I would prefer a mechanic that has more than eight years of experience to answer this question. Plus, I don’t need advice such as having someone else perform the repair.