You can only edit hours that you manually submitted and are pending approval. Please contact the event by clicking the yellow envelope icon to request a correction of approved hours.
To edit hours, simply go to your volunteer dashboard at:
https://www.eventingvolunteers.com/volunteer
and click on the "Edit Hours" button for the signup that you need to update.
Note: Click on "My Signups" and then "Past Signups" if you do not see past signups in the current view.