How do you replace belt tension-er 300te?

To replace the belt tensioner on a 300TE, first disconnect the negative battery terminal for safety. Next, remove the serpentine belt by loosening the tensioner pulley with a wrench or ratchet. Once the belt is off, unbolt the old tensioner from its mount and install the new one in its place, ensuring it is securely fastened. Finally, re-route the serpentine belt around the pulleys and reconnect the battery terminal.