air conditioner compressor replace 1991 olds 88

I am having a knocking sound from the front on idle only. I took off the belt and it went away. I am hoping that it will go away when I replace the air conditioner compressor. Can anyone share the proceedure with me? Can I just replace the clutch without releasing the freon? Does anyone know how I can eliminate the possibility of it being the air conditioner compressor?

it really could be anything the water pump the power stearing pump the ac pump you would really have to look down with the ac on and see if the ac clutch is binding up if it isnt then your ac pump should be good now when mine went bad it wouldnt knock so that leads me to believe its not the ac pump. Is your engine running hot? or making any funny noises other than the knock? Also if you do find out it is the ac clutch you can change just the clutch with a device called a puller.. (no other way to get it off) You will be able to keep all your freon.

I would be sure it was the clutch before attempting to replace it.I myself would be looking at the tensioner and water pump first.Have you tried to cycle the ac on and off to see if there is a change in the sound?