69 Barracuda Brake light switch Location

Why do you want to replace the brake lite switch? I have never seen one go bad. Very simple and reliable. If your brake lites aren't working then the problem is probably elsewhere. The switch maybe mis-adjusted. Follow the circuit. Power into the switch on one terminal and power going out the other terminal when pedal is depressed. From there to the T/S switch, then to the t/lights. Could be simple like a bad fuse.