5) Using a 3/4 inch wrench you will need to literally need the power of Zeus to relieve the tension on the tensioner by pulling the wrench towards the front of the car. Becareful it is on securely. Pull as hard as you can while a friend pulls the belt off the alternator.
This is taken from the install for the AEM
Pulley Kit. Just turn it the opposite direction stated above to tighten it.