How do you replace belt tensioner 2001 rav4?

To replace the belt tensioner on a 2001 Toyota RAV4, first, ensure the engine is off and cool. Remove the serpentine belt by using a wrench to relieve tension on the tensioner pulley, then slide the belt off. Disconnect the tensioner by removing the bolts that secure it to the engine, then install the new tensioner and tighten the bolts. Finally, reattach the serpentine belt, ensuring it's correctly aligned on all pulleys, and check the tension.