If you’re trying to change the password used to log into the SBG10’s web manager and change settings, that reference can be found here:

https://arris.secure.force.com/consumers/articles/General_FAQs/SBG10-Web-Manager-Access

If you’re trying to change the password to connect to the WiFi, then use this link instead:

https://arris.secure.force.com/consumers/articles/General_FAQs/SBG10-Changing-the-Default-Wi-Fi-Name-Password/?l=en_US&fs=RelatedArticle

Let me know if you have any questions or get stuck on a step and I’ll be happy to help!

Sometimes when you try to change the GUI password it gives you an error that the operation can not be completed or that the new password is not correct, when this happens basically you need to refresh the website and try to login again using the new password that you attempted to setup previously, if it does not work power cycle the modem and try again, if this does not work either, fact reset modem by disconnecting coaxial cable at the back of the modem, press reset button for 20 seconds with a paperclip, reconnect coax when the lights are blinking, wait for the lights to become solid and then try again the setup.