How do you put a fan belt on a 93 Mercury Topaz GS?

Loosen the alternator and take off the tension pulley. It will be a little tough to get the pully on but it is an easier then trying to fight the belt. The tension pully is spring loaded so it is a little more adjustable.

Hope that helps

In the V6, you will have a tensioner indicated in the diagram under the hood. Route the belt as indicated (if you have no sticker, go to Autozone and ask them to print a diagram for you). Then insert either a 1/2" breaker bar or a 1/2" drive socket into the tensioner's arm (square hole) to move the tensioner pulley into a position where you can slip the belt under it. (it's gonna be tight!) I found that I had to use a socket to rotate the crankshaft in order to get the belt all the way on due to the metallic knuckle that sits close to the crank pulley. The ribs make it nearly impossible to slide the belt all the way under that piece.

The rear belt is pretty much the same with fewer pulleys to deal with, but the diagram should clue you in to that.