1. Login to your admin dashboard
2. Click on Users --> View Users --> Search for the user and edit it.
3. Scroll Down to their order history and click View Details on the order you would like to issue the refund.
4. Click the Refund / Cancel link at the bottom on the charge you would like to refund.
5. Change Process Refund to Yes and then enter the amount you would like to refund. You can do the whole amount or a partical amount.
6. Click Process Refund and the refund should be completed.