We used a 1/2" breaker bar. There is a female end on the tensioner, the male end of the breaker bar fits into the female end of the tensioner. Push the breaker bar clockwise until the tension loosens but while still holding down the tensioner you have to take the belt off. Once the belt is off the alternator pulley slowly release the tensioner. Replace the belt in the same position, there should be a sticker on the underside of your hood with the diagram. Finally, push the breaker bar again clockwise to release the tension and place the belt over the alternator pulley.