You need a special tool to remove and replace the clutch. Your local auto parts store can sell or maybe rent you the tool.
You cannot change the compressor bearing, however, you can change the clutch bearing. Which one is bad? Is there a noise when the clutch is engaged, or not engaged?
AC clutch relay is inside the fuse case within the engine compartment.
The compressor should be removed with the bracket that holds it and then removed from the bracket once out of the engine bay. There is a small bracket that mounts on the front underside of the clutch that needs to be removed first (two bolts and one stud) then four bolts and one stud for the main compressor bracket.
bad clutch bearing
Best if you own a compressor, air tools keeps the clutch from turning. If no compressor, mount it in a vise to keep it from turning and remove each bolt, can be tricky as they are mounted together but turn seperately when activated.
Relatively easy for an experienced mechanic, consult the manual for specific instructions.
How do i remove an air compresser in a GMC Cheyene
Look at compressor when engine running-You should be able to see if compressor clutch is pulling in. Try with A/C on and then with A/C off to see difference
You are low on refrigerant, google R134a...
Replace the fan clutch that is on the front of the engine.
Low or no freon will cause the AC not to work. Also if the clutch on the AC compressor has failed, or if the compressor itself failed.
The Dark Green Wire should be the hot to the air compressor clutch and Black should be ground.