Replacing an O-ring is a common enough task, which for the uninitiated is a bit tricky. Generally, no tools are required; but the fit of the O-ring on the land is so tight that "you can't get there from here." And there are numerous other lands on the way. It helps to see an experienced pair of hands do this expertly.
Excerpted from a longer movie that shows the entire process of rebuilding a typical faucet. The longer version is the type of movie maintenance personnel might use. The two short excerpts depict specific tasks, excerpted for emphasis, so they can be used as FrogOJT movies -- rapid skill acquisition thru digital video technology. The longer form movie showing the entire process merits it's own CD-ROM-- because maintenance is a different philosophy, a different pace, from production work. There's a higher percentage of problem solving. in the mix.