Its pretty easy to do. Remove the belt, find the tensioner and there is a square hole in it for a breaker bar or large 3/8's ratchet. Insert the breaker/ratchet and remove the tension and pull the belt. then remove the wires from alt. afterwards pull the 2 bolts. reverse steps to install new alt. The big question is are you sure its the alt and not the battery?How do you change an alternator in 2003 gmc envoy?
If you buy it at Auto Zone they will show you how.
