Before you can clean an abalone, you need to get an abalone. Commercial fishing or diving for abalone is illegal on the West Coast, where abalone live and grow. Recreational abalone diving is tightly regulated where it is allowed. To meet the demand from people who love abalone but aren't fit (and crazy) enough to dive for them, clever folks have figured out how to farm abalone. Abalone grow slowly and the process of raising them is a laborious one (see a Visit to an Abalone Farm
In short, if you have a fresh abalone, either you dove for it, someone who must love you dove for it, or you spent a pretty penny buying a farmed one. In any case, you'll be happy to learn that cleaning it and preparing it to be cooked is a surprisingly easy process.