Disconnect the fuel filler hose, drop the gas tank, remove the pump.
Dodge doesn't have a 4.8 liter engine so I am not sure that there is an answer.
The pulley is pressed fit onto the pump. It will not come off the pump. You have to replace the pump to replace it.
how do i change a water pump in a 1991 dodge shadow with a 2.2 liter does it require an internal water pump
very carefully.
The water pump is located inside the front of the engine, driven by the timing belt.
inside the front of the engine, driven by the timing belt
Front of the engine, the fan screws onto it.
the water pump is on the bottom of the engine underneath the alternator
It is inside the engine, driven by the timing chain.
Drain the water from your 1991 Dodge Caravan 3.3 liter engine cooling system. Remove the water return hose from your water pump. Remove the water pump belt. Remove the water pump retaining bolts. Reverse the process to install the new water pump.
If you have a 3.5 liter motor, take it to an independent shop, I would not recommend it for d-i-y ers.
If it is a 3.0 liter, It is a very difficult job. Water pump runs off timing belt behind all the plastic panels and motor mount on front of engine. Haynes/Chilton book has the procedure but it is not for the mechanically challenged.