1. Tools needed: Flat tip screwdriver, ordinary electrical tester and sometimes, needle-nose pliers

 See inside breaker box

4. No main shut off? 
Or replacing main breaker, you need to pull meter to turn off electricity <> call electric company

5. A license might be required for a ‘meter pull’ or a ‘smart-meter turn-off’

6. If no license is required, electric company will remove locked collar from around electric meter, for a charge

7. Before pulling meter, turn off all circuit breakers in main breaker box

8. Pull meter out to turn off electricity <> the meter has 4 prongs that stab into meter box, similar to an extension cord plugging into a wall socket <> the meter is held in place by friction, there are no screws

9. Pulling meter requires a stout pull downward and then upward <> usually you pull downward on top of meter and then push up, going up & down to loosen and remove meter > removing meter will turn off electricity to whole house including breaker box <> however meter box will still have live electricity <> stand on dry boards when pulling meter <> turn off all circuit breakers in main breaker box before pulling or re-installing meter

10. Do not put hand or screwdriver inside meter box > meter box still has live electricity > if kids are around, they will play with meter box after you go inside to change breaker > for safety around kids, turn the meter upside down and push it back into place.

11. After work is finished, stab meter back into box and household electricity will resume. Electric company drops by later and puts collar back on [do not tamper with meter, they will find out and put your brother-in-law in jail]

A METER PULL IS NECESSARY ONLY WHEN BREAKER BOX DOES NOT HAVE MAIN SHUT-OFF or if you are replacing main breaker

12. If the breaker box has a main shut off, a meter pull is not necessary. Turn off main breaker and remove front panel to reveal breakers

13. Do not stand on bare soil or damp surface of any kind when working with electricity

14. Lay plywood or boards down so you do not contact any possible ground surface

15. Wear dry clothes and dry shoes <> read these instructions carefully <> and don't sweat

16. Do not lean against or touch washing machine or any metal pipe, metal duct or metal object

17. Use extreme caution inside breaker box <> the big wires that attach to main breaker are still hot unless meter was pulled > do not touch or get near the main breaker see image

18. Notice there are two vertical rows of breakers

19. Behind each breaker is a busbar > there are two busbars, one for each row of breakers 

20. Busbars carry electricity from main breaker to the individual breakers

21. No screws hold breaker to breaker box. Breaker attaches by friction <> breaker end with a wire snaps onto a cleat or metal rod, the other breaker end ‘stabs’ onto busbar.

22. Breakers have one or two wires attached with a screw <> these are hot wires <> 120 Volt breakers have one hot wire <> 240 Volt breakers have two hot wires <> notice that white wires and bare copper wires attach to exposed metal bar called the neutral busbar <> it is safe to touch neutral busbar assuming white and ground wires are not loose.

23. Double-check electricity is turned off. To do this, leave individual breakers turned on

24. Put tester on breaker screw where wire attaches and touch other prong of tester to neutral busbar where white wires attach <> or test between screw on breaker and nearby copper ground wire or bare metal part of breaker box.

25. Test several breakers to check electricity is off

26. If electricity is on, you can proceed at high risk: be careful not to touch hot busbars <> for safety, turn off all individual breakers

27. Replace the breaker: mark bad breaker before removing cover <> use digital camera to record images if necessary

28. Remove wire(s) attached to breaker (the wire-end of breaker is attached to a metal rod or a cleat) 

29. Breakers are held in place at both ends <> one end locks into a cleat -or- snaps onto a bar <> other end of breaker rotates to busbar and then 'stabs' onto the busbar see image

30.Remove breaker <> start at end with no wire <> remember this end of breaker is stabbed onto the busbar and it is usually pretty tight <> put a small flat-tip screwdriver between breakers and gently pry breaker up and off busbar

31. Once breaker is loose, it will rotate out > sometimes old breakers fall into pieces > make sure these pieces don’t drop behind the other breakers > use insulated needle nose pliers to remove all pieces > if main breaker is turned off, and you checked with a tester, then busbar carries no electricity and is safe to touch while removing broken circuit breaker. 

32. Burned and damaged busbar? Look at busbar where bad breaker was connected > if busbar is burned and broken, then new breaker will have to fit into another slot

33. If you do not have another slot available, then there are three solutions: 
        A. Buy a tandem breaker with same Amp rating as replaced breaker 
        B. Double up on another breaker with same Amp rating
        C. Install a subpanel* Read more at bottom

34. When no extra slot is available, easiest solution is tandem breaker. If no tandem breaker is available, then you can double up on another breaker and that breaker will now serve 2 circuits. Doubling up is ok for 120V circuits. 

34a. Note difference between 120V and 240V: Doubling a burned out 240 breaker invites more problems. For 240V breakers, a subpanel is better idea since each 240V appliance is given its own dedicated breaker to meet specific amp draw of that appliance.

35. If you double up, then double on same size breaker as being replaced > so, if bad breaker was 20 Amp, select another nearby 20 Amp breaker. Do not attach wire to breaker rated for more amps than original <> for example damaged breaker was 20 amp, do not double on 30 Amp breaker <> connecting wire to oversized breaker is clear fire hazard especially since replaced breaker burned up most likely from heavy use.

36. When you double up, refer to your panel door where all breakers are labeled and find which nearby breaker is not being used heavily > then attach wire from bad breaker to the chosen double up breaker. It may be necessary to add additional length to wire to reach double-up breaker <> use same gauge wire. See standard wire gauges 
See how to twist wire together <> See how to select wire nut

37. Avoid doubling up on a 'dedicated' breaker <> for example a microwave oven usually draws so much wattage that a single breaker is dedicated to that appliance. Avoid refrigerator breaker for same reason. When in doubt, simply add up wattage of each item drawing power from breaker <> take total wattage and divide by 120 V <> this gives total Amps on that circuit <> if the Amp draw is lower than your 20 Amp breaker, then the circuit should be safe. Read about Volts, Amps, Watts

43. To prevent later problems, tighten screws on other breakers <> DO NOT touch main breaker or wires going to main breaker

44. Tighten screws on neutral busbar where the white and bare copper wires attach <> be very careful around main breaker <> don’t let your screwdriver slip

44. After screws are tight, re-attach front cover panel temporarily with 2 screws

45. Turn on main breaker and check new circuit

46, If circuit is working, then finish by putting all screws on cover panel > wiggle panel around so screws go in > extra panel screws available at home center

46. Cover must be tight to prevent sparks from exiting breaker confine