To replace the bearing on your A/C compressor requires a special tool for removing the clutch and another for putting it back on. As I recall, a thinwalled 7/16" socket is needed to get the nut off the compressor shaft, (snap-on's always worked best for me) and a good air ratchet makes the job quick and effective. once the clutch is removed, a snap ring about 1 1/4" dia is all that holds the bearing/hub assembly in place. You might do best to buy the whole clutch/bearing assembly as a package.
When reinstalling the clutch, leave a gap of roughly 1/8" between the clutch and bearing hub assembly. You can use a nickle as a guage.
The cost of the tools to do the work will probably exceed the labor fee you'll pay someone to do the work for you, and the only thing they are good for is A/C clutches.
I've been out of the automotive A/C business for a few years, but I doubt much has changed in the construction of A/C clutches.