Admins can visit the Registrations section from the event management screen to edit/cancel registrations. Clicking the red Cancel icon to begin cancellation. You will be prompted to confirm this step.
If the registration has already been paid, clicking Cancel issues a credit for that member or non-member to be used on future transactions. Cancelling an event registrations will not refund a users payment.
If the registration has not been paid or did not require payment, this step also deletes the pending transaction. You will then see a Delete icon that allows you to delete the cancelled registration completely (so that it no longer appears in the list.)