Heads up: Be sure to jot down your custom settings, like your static IP address if you have one, or your Wi-Fi® network name (SSID). You can then change them back after the factory reset.
Press and hold the gateway Reset button for at least 10 seconds. If you let go before 10 seconds, the gateway will reboot, but it won’t reset.
Wait until the gateway restarts and all the status lights are lit.
See if the Broadband or Service status lights are solid green. If so, the reset worked.