How do you repacle the serpentine belt on a 2007 Saturn Ion?

To replace the serpentine belt on a 2007 Saturn Ion, first, ensure the engine is off and cool. Locate the serpentine belt tensioner and use a wrench or socket to rotate it and relieve tension on the belt. Remove the old belt, then route the new belt according to the belt routing diagram usually found on a sticker in the engine bay. Finally, release the tensioner to secure the new belt in place, and double-check the routing before starting the engine.