I just replaced all the guts in my toilet tank. The ballcock was worn out and the flapper valve wasn't flapping. I bought replacements at [local Big Box], and although it took me two tries to get everything tight enough that I had no leaks, IT"S WORKING!
My wonderful son-in-law came over yesterday to install a replacement for my 11-year-old disposal (the switch stopped working and a replacement part cost over 10% of the unit - ugh). I had an almost new disposal stored downstairs, hoping to eventually get a small kitchenette set up, using all the old sinks and appliances from my original before-the-major-remodeling kitchen. So, we hauled the almost-new one up, and DSIL went to work. He had to do some creative carving on the cabinet, it was a smidge too large for the space, and re-align some of the pipes, but he got it in and tested, so I'm back in business.
And, of course, while I had him here I asked him to do several other small plumbing jobs, which he was happy to do. However, he took the toilet ballcock out, and then we discovered I had purchased the wrong replacement part. He had to quit last night (and thank goodness I have another bathroom on this floor) so I tackled the job today. It feels so good to do "man's work" successfully.