Pulling the upper motor mount on the left side of the engine (as you stand in front of the car w/ the hood open) certainly makes it easier to get that belt back on. The way I did it was have one person pulling the tensioner back and another fighting w/ the belt to get it over the A/C pulley. The second person reached down to get to the A/C pulley, and having that mount out of the way made it easier to get to.
What makes you think the belt is bad? Just some squeeking? Could be the idler pulley...
