This depends if you set up your G36 using the web GUI or the SURFboard Central App.

If you used the app, the login info for your G36 will be in the app. The username to login is the email address you used for the app, and the password is listed on the Access Web Interface page of the app (you can get to that via the hamburger menu). This link will provide more info on how to use that if needed:

https://arris.secure.force.com/consumers/articles/General_FAQs/SURFboard-Central-Web-Manager-Access

If you no longer have the app installed, or if you set up the modem using the web manager and have forgotten the password, you’ll need to factory reset your unit and reconfigure it. Keep in mind this will remove all settings, so you will need to reconfigure your device.

To reset, find the small reset hole on the back of the modem and use an unwound paperclip or similar item to hold the button for 20 seconds. This will reset the unit to the default settings after a couple minutes; you should be good to go once the light stabilizes. Then when you go back to the modem’s login page, it will ask you to set up a new password. The username will be “admin.”

If you onboard again with the app, then the email address you used for the app will be the username, and the password will be in the app as noted above. If you plan to use the app, make sure you onboard with the app first instead of customizing the web GUI!