How do I unplug the switch for now until I can get it fixed

 

if i can remember correctly its a white clip right where that button piece broke off. Its right on the shaft of the brake pedal.

 

You can also ghetto rig it and duct tape some pennies, metal washers, etc, to the brake pedal lever, so that it depresses the brake light switch, when you're not using the brake pedal.

I too had the same issue with my car and the same exact piece you are referring to, broke in mine as well. POS Mitsus.