What you need is a longer handle or slide a piece of small pipe over the top of your wrench too give you more leverage and so that you can move more freely with your other hand to remove the belt. Once you get the tensioner released slide the belt off of the idler pulley from there it should be fairly easy.
There is usually a diagram somewhere in the engine compartment that shows the treading of the belt. You can go to the Chrysler or similar website and they should have information concerning this project. There is a tension bar that you need to loosen in order to take the belt off and also tighten on reinstall.
Iis there a diagram for putting the serpentine belt run on a 1994 chrysler van
Don't remove any pulleys, there should be a tensioner along the path of the belt near a pulley. Tensioners are long bolts that adjust the pulleys. Just loosen it enough to release some of the tension on the old belt and put the new belt on the same way the old one was fit on. Theres usually a little belt diagram on a sticker on the bottom of the hood of vehicles, if there isn't just make sure you remember how the original belt was routed. I wouldn't cut the belt because if you're just replacing the belt due to wear and you the new one isn't quite right you probably won't be able to drive very far if you don't have another vehicle. Good luck.