This is a boring post as it concerns a part of the computer that hasn't received media attention or reached the glamorous recognition some of the other PC components have - it's the power supply.
After all of these years in the field I still do what would be considered boring or beneath stature jobs. I don't care, the pay is the same. Another reason that a task such as this is that it's simple. Changing a desktop computers power supply takes a low amount of mental energy that it's almost relaxing. It's mostly a physical labor thing with just a few minor technical points to remember. If they all go as smooth as the this one then bring them on I say.
This was an old PC and it was using an AT style power supply, not even an ATX. One of the basic differences between the AT and ATX is the motherboard connectors. The old on came out without a hitch and the new one when in with even less trouble. The power button lined up right away and the whole thing was wrapped up in 20 minutes. All jobs should go this way.