1) Open the link "Configure Per Store and Backup Gateways" in the Configuration - Site Configuration Wizard under the "Payment Gateway:" section, and edit as desired for the available fields. 2) Configure the backup payment gateway using the "configure" link to the right of the gateway in the listed Payment Gateways. Do not attempt to set the radio button for the backup gateway. NOTE: If you need to change this or blank it out, you need to change the PaymentGatewayBackup AppConfig directly. NOTE: The Primary Gateway Reties and Backup Gateway Retries settings control how many times the software will try to contact the primary and secondary gateways respectively before displaying an error to the customer. Do not set these too high, or the delay may cause customers to give up.