How do you replace an idler pulley on a 1998 Mercury Villager?

To replace the idler pulley on a 1998 Mercury Villager, first, disconnect the negative battery terminal to ensure safety. Next, remove the serpentine belt by loosening the tensioner pulley with a wrench, then slide the belt off the idler pulley. Unbolt the old idler pulley using a socket wrench, and install the new pulley in its place. Finally, reattach the serpentine belt and reconnect the battery terminal.