One word: don't! Unless you want your piano to be nothing more than a piece of nice looking furniture, that is! Professional piano tuners go for at least 2 years of intensive training to learn their skills. There is much more to it than meets the eye (or ear). It might seem a bit expensive, but you are paying for a highly skilled technician to do a job beyond the abilities of the best musicians. Don't skimp, if you want your instrument to remain in good playing condition!
Mrs. King recommends Robert Fisher at MrPianoTuner.com in Crystal Lake, IL