My convoy knob remains in tact, but it lives behind the center console., hidden from view. I bought a civilian light switch, plugged it and voila, all works like a civy truck.
There are a few threads about this very switch. Some say that they simply disconnected the switch, while others needed to jumper part of the harness where the switch plugs in to. I wasn't happy with any of the jumpers I could make with aftermarket bullet connectors and didn't want to buy a $60 bullet crimper. And everything worked with the switch still installed, so I kept it as original as possible.
On a side note, you'll need this if you don't already have it. Don't use a civilian wiring diagram with an EXMOD.