As a homeowner, you can usually do your own work, however, that requires that you follow the code and do it properly. I installed my own gas range a few years ago. When we built the home 34 years ago the code allowed for using soft copper tubing for propane inside of the residence. Today the code is all iron pipe, so I removed all the existing copper tubing and installed new black iron piping according to the current day code. The only thing that I couldn't find at the local plumbing supply store was the short pipe that is used to connect 2 pipes together. It is about 12" long and has both a left and right handed threads on the end, and a left handed by right handed threaded coupling on one end. This pipe is used in place of a union. Since the plumbing supply parts person told me that the plumbers were still using unions, I used a union also.
The same with electrical. When we put an addition onto the home, it required moving the electrical service entrance. At the time we also installed a whole house generator and automatic transfer switch. This required a service disconnect in front of the transfer switch and after the meter. Code required that the original panel have all the grounds and neutrals separated. I shut off the power, and using a bright battery powered work lamp, I removed the bonding screw, installed a new isolated ground bar, and moved all the bare copper wires over to the new ground bar. I also had to replace the grounding wire and pull a #4 copper ground wire through all the ground rods on the electrical system and take that uninterrupted wire to a grounding lug on the steel well casing. The electrical inspection was done and passed. I don't believe in taking short cuts with electrical, gas, water, or sewer.
