The plot is simple: a new boss now owns the garage Fonzie works at, then Fonzie quits due to ridiculous demands by the new boss, and tries out a bunch of jobs.
This episode is fun to watch mainly because of the guest stars. The new boss at the garage is none other than the great Richard Stahl, a TV legend especially in the 70s, a guy whose face everyone knows even if they may not know his name. Stahl is sharp as a tack as always and a blast to watch.
When Fonzie tries to get a business loan, the loan officer is none other than Dick Van Patten, yet another TV legend. With these guests, a show is always worth watching.
One particularly funny sequence is Fonzie going door to door (with Richie's help) selling encyclopedias, and encountering a bunch of different people. The last door he tries is answered by a gorgeous woman, who invites Fonzie in, leaving Richie carrying the bag, literally.
There's even somewhat of a risque finale, as Richie, Potsie, and Ralph all go to the woman's apartment (one by one, unaware of the other) and she invites them all inside, presumably to have a good time with. Of course, the Fonz then comes around and kicks them all out.
We also get a great view of Ralph's hot rod in the garage, so that's another bonus. Overall, a decent episode for one being after the first two great seasons.