You need to go to a car parts store, and get a repair manual for your car. They cost about $16.00 Or, go to a Public Library.
how do you replace ignition switch on a 1992 Chevy cavalier 2.2 4 cylinder
the 3.1 liter v6 and the 4 cylinder both have sepentine belts
Replace serpentine belt on Chevy avalanche?HOW
Remove serpentine belt. Remove alternator. The bolts that hold the tensioner on are under the alternator.
Providing your cavalier has a 2.2l, this is what your looking at.
How do you remove and replace wiper switch on 2002 Chevy Cavalier
If you have a 2.2 liter 4 cylinder, the water pump is under the alternator on the passenger side and below the serpentine belt tensioner.
How to remove and install the serpentine belt on 1991 Chevy Blazer with AC?
The Front-Passenger-Side Cylinder
This diagram is under the hood. Look for it
Try this link it even has photos http://www.v6z24.com/howto/heatercore
Remove the water supply hose from your 1988 Chevy Cavalier thermostat housing. Remove the thermostat housing bolts. Lift the old thermostat out and drop in the new thermostat.