How change serpentine belt on a 2002 dodge diesel?

To change the serpentine belt on a 2002 Dodge diesel, first disconnect the negative battery terminal for safety. Use a wrench to relieve tension on the serpentine belt tensioner, then slide the old belt off the pulleys. Route the new belt according to the diagram usually found on a sticker in the engine bay, ensuring it's properly seated on all pulleys. Finally, release the tensioner to apply tension to the new belt and reconnect the battery terminal.