How do you replace the fan belt on a 1996 Buick Riviera?

To replace the fan belt on a 1996 Buick Riviera, first disconnect the negative battery terminal for safety. Loosen the tensioner pulley using a wrench to relieve tension on the belt, then remove the old belt from the pulleys. Route the new belt according to the diagram usually found on a label near the engine or in the owner's manual, ensuring it sits properly in the grooves. Finally, re-tighten the tensioner and reconnect the battery terminal.