I did this on my 89 Big Block GMC, but it is virtually the same for all AC units.
You will just have to buy the right tool for your compressor type.
It cost me about 100 bucks total. No removing the compressor or costly recharge.
Ok so I had a whirl, it wasn't the compressor just the pulley.
I got the pulley and clutch for 81 dollars. I bought the AC clutch install and removal tools on line for 26 bucks. Auto Zone only has the Ford crap.
So here goes...This is for obs, but all ac's are similar.
You need (obs 454 w/R4 compressor.) to remove the fan shroud.
(10mm bolts) 7 plus one for the coolant hose.
Next you have to remove the belt. Pause for a sip of beer.
Next step is to remove the center bolt from the saft on the compressor (14MM) You can use a special tool to hold the clutch or a flat tipped screw driver. I rented the tool from Auto Zone.
It has tree prongs that fit in the compressor and a hole to get at the nut.
One the nut is removed it is time to get the clutch off. The clutch is treaded on the inside. The tool screws into it and has a center piece that pushes against the shaft.
Just hold the end screwed into the clutch and turn the one that presses on the saft and it will pop right out.
Underneath mine looked like this all the grease was coming out of the bearing.
Under all that grease is a snap ring that must come off.
This is what it looks like.
Next the pulley has to come off. Mine popped right of with a pry bar and a little push against the compressor. They do make a special A/C pulley puller but I didn't need it.
The pulley is actually pressed on to the compressor body.
Here is what it looks like removed.
You can see the grove where the snap ring was.
Ok have some more beer and clean up the compressor.
Now you are ready to install the new pulley, It will slide on a bit, but I used a board and hammer to get it the rest of the way on. I put a little grease on it so it would slide better. I couldn't find a tool that would press it back on.
Once you have the pulley on, install the snap ring.
Now it is time to install the clutch. NOTE*There has to be .20 to .30 air gap between the clutch and the pulley*NoteThe clutch is keyed.
Slip it on the shaft, this is when you need the clutch install tool.
It threads over the shaft and there is a piece you screw down on it that presses the pulley on. Screw the installer ALL THE WAY onto the shaft
or it will keep backing off the compressor shaft.
You hold the outer most portion and turn the inner big piece that just pushes the pulley on. Use a feeler gauge to check air gap.
Once that is on, remove the tool, put the bolt back on, reinstall the belt and Fan shroud.
You saved some cash! No replaceing the compressor or getting a recharge.
Hope this helps.
This is the clutch puller
This is the clutch installer
This is the part of the installer that screws onto the saft.