If you have device connected to modem Wi-Fi network or any on direct connection you can follow the steps mentioned on the below article to change the Wi-Fi credentials.

http://arris.force.com/consumers/articles/General_FAQs/G34-G36-Changing-the-Wi-Fi-Name-and-Password

I tried this but rather than getting the https:// Redirect page, i got this notice.

This site can’t be reached

192.168.0.1 took too long to respond.

You can try accessing the web page with different browser such as Microsoft edge, internet explorer.

If the same problem persists, please help us with the model number to assist you on this.