How do you loosen and replace an alternator belt on a '91 Olds Cutlass CIS 4 door sedan?

iT IS SIMPLE, fIND THE BELT TENTIONER, IT IS A SPRING LOADED ARM WITH A 3/8" square hole in it near the idler pully, use a 3/8" rachet or braker bar to move it up, this will release the tension on the belt, be sure to rout the new belt properly! clay