You will need the Write Notes permission to perform this action.
Navigate to the person who has the note you want to delete and click on the "Notes" tab. Next, locate the note you want to remove and click on "Delete" from the drop down at the end of the row.
A confirmation pop up will appear. Click on "Yes" to finish.
Helpful Tip
Notes of type "Archived Notes" and "Unarchived Notes" cannot be deleted.