Replacing serpentine belt on 1996 Dodge Grand Caravan, do I need to access tensioner pully from under the car? The tool from the shop won't move far enough from the top to release the tension. Thank You

This is the procedure for 3.3 and 3.8L engines:

1. Disconnect the negative battery cable.
2. Raise the front of the vehicle and safely support it with jackstands.
3. Remove the right front splash shield.
4. Release tension by rotating the tensioner clockwise.
5. Remove the belt and install a replacement.
6. Proper belt tension is maintain by the dynamic tension.
7. Install the right front splash shield. Lower the front of the vehicle.
8. Connect the negative battery cable.

The bottom may be better, you are right, the long version of the removal tool at local parts places wont give you enough room to loosen the tensioner. You can get a kit at sears that has a shorter version with sockets this one works or use an offset box wrench 15mm to get it from the top, a socket set won't do it since there is no clearance for the socket wrench and socket.