Stab-Lok circuit breakers are easy to replace because they snap in place. They often need to be replaced because they lose tension and arching occurs between it and the buss bar. This is extremely dangerous because it causes the panel to overheat, which can result in an electrical fire. If you hear a buzzing coming from your panel or the panel is hot to the touch, you may need to replace one or more breakers.
Position the work light to shine on the panel. All the lights will go out as soon as you turn off the main circuit breaker, so you will need this light to see.
Turn off the main service breaker. It's a large, double-pole breaker located at the top or bottom of the panel. It has the highest amperage in the panel.
Remove the screws holding the circuit breaker panel's outer cover in place. Set the breaker panel cover aside. Replace the screws in the panel box for safe keeping. Remove the cover over the circuit breakers and the circuit breaker wiring. Use caution when removing the breaker cover because the panel's main lugs will still be live even with the main breaker in the off position.
Turn on the voltage tester and bring it near the screw terminals on the breakers. If there is still power present, the tester beeps loudly. If the panel is safe to work on, the tester remains silent.
Remove the branch circuit wire from the circuit breaker's screw terminal by loosening the screw and pulling the wire straight out. Move the wire to the side of the panel.
Pull up on the end of the breaker nearest the centre of the panel. In some cases, you may need to pry it up with a flat-blade screwdriver. Place the screwdriver between the breaker to be removed and the breaker opposite, and use the opposite breaker as a fulcrum point. Slip the breaker off the rail tab located at the screw terminal end.
Install the new breaker by slipping it over the tail tab. Press it down on the buss bar. Reconnect the circuit conductor and close up the panel. Turn on the main breaker.