How do take off the old serpentine belt in a 2001 jeep Cherokee sport?

use a 15 mm box end wrench to loosen the bolt which runs through the center of the tensioner pulley - turn it counter-clockwise. next, use a 15 mm socket to loosen the tensioner bolt - again, turn counter clockwise to loosen. remove the belt and replace with new one. turn tenisoner bolt clockwise to tighten belt. tighten bolt through center of pulley. put some belt dressing on and you are good to go!