Open a web browser and go to `http://10.0.0.1`
Sign in with your Xfinity admin username and password
Select `Gateway`
Select `Connection`
Select `WiFi`
Choose the band you want to change, such as `2.4 GHz` or `5 GHz`
Find the `Password` or `WiFi Password` field
Enter your new WiFi password
Click `Save Settings` or `Apply Changes`
Reconnect your devices using the new password