Hi Gary,

If you haven't written the harmony notes to the track, you could go to Harmony - Melody Harmony (select), and choose 0 <no harmony.

If the harmony has been written to the track (last two steps in Noel's picture) and the song has been saved, then it can only be removed by deleting the harmony notes one-by-one, using the Notation Window or Piano Roll.

Thanks
Kent
PG Music