Pull out the HVAC control panel.
On the back of the selector switch is a (I believe) 2 wire connector. All you need to do is cut one of the wires and bring the ends to a switch. You can then choose switch ON - normal operation, switch OFF, no AC. What you are doing is preventing the PCM from seeing an input calling for AC. A small round push-on/push-off switch cleverly located in the control panel could even look stock. Careful to make sure it doesn't damage any circuit when you drill the hole.
Yes -- my TJ has aftermarket AC and it runs when in certain positions on the selector dial. I put the switch in mine because I do like to run standard vent air when sitting in traffic with the top down and doors off. In this situation, AC seemed pretty dumb. Still kinda curious if a different AC control panel (from a '99 or '00 jeepw/stock AC?) would connect OK in my vehicle.