How do you Change the idler pulley on a 96 eldorado?

1. Place a three-eighths-inch ratchet driver into the square hole on the face of the tensioner pulley. The idler pulley is bolted onto the side of the engine block and does not attach to any other accessories. 2. Pull up on the ratchet handle to release tension on the Cadillac's serpentine belt. Pull the belt off the tensioner pulley. Don't remove the belt from any of the other pulleys. 3. Remove the two bolts that secure the tensioner arm to the engine block using a socket and ratchet. The pulley permanently mounts to the tensioner arm. 4. Remove the tensioner arm and pulley from the engine bay.