Play the song and have students listen to it carefully so as to understand as much as possible at first hearing.
Ask what the song is about and then ask students if they know what homophones are. (It helps my students to mention synonyms here and explain if needed.)
Tell the students they will get a worksheet with lyrics to the song, but almost every line has a mistake, ,where a homonym is used instead of the right word.
Play the song again twice and have them correct as many mistakes as they can.
Go through the lyrics helping them if/when necessary.