Navigate to the payment you want to refund and click 'View'
This will then display the 'Edit Payment' screen. You can edit different aspects of the payment here. To refund the payment, click 'Refund.'
Clicking on 'Refund' will then bring you to the 'Create Refund' screen. Simply fill in the details relating to the refund and click 'Refund.'
It will then refund the payment, displaying the 'Edit Refund' screen. This will show all of the details of the refund. To confirm, click 'Update' and to cancel or remove the refund click 'Delete this refund.'