Once you have added a note to your Event, you have the option of going back and deleting your Event Note later. To delete your Event Note, you will need to click on the Event Note on your Calendar, you will then need to click on the "Edit" button at the bottom of your Event Note, and then click on the “Delete” button at the bottom of your note. Please make sure that you want to delete your Event Note before you delete it. Once the note has been erased, there is no way to undo this action.
Follow the steps in the image below to delete you Event Note: