From the event Dashboard, click on Manage next to the registration, then click on Edit Registration / Partial Refund. Here you can edit the registration information as well as change ticket quantities. As the admin, you can edit the sub-total and tax directly, to accommodate discounts, etc. Make sure to edit these amounts after completing any changes to the tickets, as selecting tickets will re-calculate the sub-total and tax.
If the final amount is less than what was originally charged, we will process a partial refund for the difference.

Fees
for transactions and refunds vary according to the terms between you
and your payment provider. Please refer to the credit card processing
fee policy with your payment gateway for more information about whether you will be responsible for any fees.