How do you change the serpentine belt on a 2003 ford excursion with a 6.0 diesel engine?

To change the serpentine belt on a 2003 Ford Excursion with a 6.0 diesel engine, first, locate the belt routing diagram, usually found on a sticker under the hood. Use a wrench or ratchet to relieve tension on the tensioner pulley and remove the old belt. Then, route the new belt according to the diagram, ensuring it sits properly on all pulleys. Finally, recheck the belt's alignment and tension before starting the engine.