How do you take the alternator belt off of a 1995 Pontiac Grand Am?

On the 4 cylinder engine, there is an belt tensioner right under the alternator pulley and slightly back. It keeps spring loaded tension on the belt so that you don't have to ever adjust the belt tension. Put a 15mm wrench on the tensioner pulley bolt and push towards the back of the car. This will allow enough play in the belt that it can be slipped off the pulley. Be careful when replacing that the grooves are properly seated in all the pulleys or the belt can be destroyed in very short order.

The V-6 engine is probably similar.

Good luck!