1997 Chevy Cavalier disconnecting AC compressor

The a/c compressor clutch is electric. Simply unplug the electrical connector that plugs into the a/c clutch. Your check engine light will come on but it should not effect the engines performance.
Be aware that your defrost works on conditioned (dry) air. It will no longer keep your windows from fogging up but it will blow heated air to thaw out the ice on cold days.
The rattle may indicate that your refrigerant needs a little charge. Any autoparts store sells small cans of refrigerant, they even come with a pressure gauge to be sure you put enough in.