In the 1950s and 1960s, most cars were equipped with manual brakes, and braking was quite a chore. Then the brake booster was introduced, using vacuum from the engine to provide extra power to the pedal, decreasing the amount of pressure that the driver has to exert. If there is a vacuum leak in your booster, or it's not performing well, you'll need to remove it. This should take about a half-hour. The project vehicle is a 2001 Chevrolet Silverado. The process is similar for other vehicles.
Pop the hood and unbolt the master cylinder from the brake booster using the open-end wrench set. The master cylinder is the portion which has all of the brake lines running into it. Once it's unbolted, pull it forward off of the booster and let it hang.2
Crawl underneath the dashboard and use the flashlight to light up the top of the brake pedal. Follow the pedal vertically into the dashboard with the light. You'll see a clip that holds together the brake light switch and the connection to the booster. Use the flathead screwdriver to pry off this clip, then place it to the side. Once it's off, you can disconnect the linkage and brake light switch by pulling them off the pedal.3
Use the 3/8-inch ratchet, extension and sockets to remove the four bolts that hold the brake booster to the firewall. You may need a 3/8-inch universal joint on the end of the ratchet to get into some of the tighter spaces.4
Go under the hood again and pull the brake booster out from the firewall, using your hands. The booster is now freed from the vehicle.