How do you install a brake light switch 1970 Volkswagen beetle?

There are actually two brake light switches. Remove front tire on the drivers side. You should be able to see the master cylinder. There are two electrical plugs going to the two switches front and rear. Unplug the one you think you need to remove. Spray some penetrating oil on the connection and take a break. A 1" wrench should fit, the shorter the better. Turn counter-clock-wise to remove. You have a very tight space to work in, so it will only move a small amount. Make sure you check to figure out which switch needs to be replaced. You can do that by unplugging the front switch and see if the brake lights come and, then unplug the back switch and try again. If the lights don't come on with one or the other, then both may be bad. Good luck.