Choose a song to parody. The song of choice should be popular, with a distinct beat that will be recognizable to most people without the original lyrics.
Compose your original comedic lyrics. Twist the original lyrics so that your parody makes fun of the song or the topic of the song. Try to make your new lyrics flow as well as the original did by using words with about the same number of syllables as the original verses.
Copyright your new song. Visit the U.S. Copyright Office's website at copyright.gov and follow the directions to file a copyright registration. This costs $35, and it can take four to five months for you to receive your copyright certificate.