Remove the bolt holding it on, pull it off with a puller and press the new one on,
very carfully
for a 1994 Grand Caravan (probably like the 1995) see: How do you replace the headlight assembly located on a 1994 Dodge Caravan? for a 1994 Grand Caravan (probably like the 1995) see: How do you replace the headlight assembly located on a 1994 Dodge Caravan?
If you mean crank pulley, the water pump has failed.
the 1995 and before 3.0L's only have the sensor in the distributor. No crank sensor.
With tools.
See page 3 or 4
disconnect the battery, remove the bolt in the center of the pulley, then use a harmonic balancer tool to remove it
It is behind the Crank Pulley (harmonic balancer). You will need a special puller, and a 1/2 in impact wrench. You must remove the RF wheel, and inside fender cover to access.
The tension spring is broken, and the entire assembly must be replaced.
Very front of the engine, under the housing behind the crank pulley.
I gave a detailed procedure on page 3or 4.
Replace the gas cap first.