It really depends on make and model of car but I its a newer auto you have to look for the tensioner which will have a square slot on it where you can use a 1/2'' drive ratchet to loosen the tension so that you can install the belt and if it does not have a tension pulley there will be adjustment screws on the bracket of the pump that you will have to loosen and then slide the pump so that the belt will go back on
