You dont need to remove the AC compressor or alternator. It helps but is not neccessary. Here is how I do it.
Remove belt.
Loosen the high pressure line where the hose attaches to the steel tube that runs around the pump.
Remove the pump feed hose from the pump. Catch any fluid left in a container.Do not reuse any fluid.
Remove the two 13mm headed bolts that hold the pump to the bracket. Access the bolts through the holes in the face of the pulley.
Remove the pump from the car. You may need to remove the MAF,tube and whatever filter you are running to get the pump out through the top. It drops out the bottom if you are running a stock IC.
R&R the pulley.
Reverse procedure to reinstall. Add the correct PS fluid and bleed the air out of the system and you should be ready to go.