How do you change idlers pulley on a 1997 Oldsmobile Aurora?

To change the idler pulley on a 1997 Oldsmobile Aurora, first, disconnect the negative battery cable to ensure safety. Then, remove the serpentine belt by using a wrench to relieve tension on the tensioner pulley. Next, unbolt the old idler pulley from its bracket, replace it with the new pulley, and secure it in place. Finally, re-install the serpentine belt, ensuring it's properly aligned, and reconnect the battery.