On the device that’s already connected to the Arris modem’s default network, go to the web browser and enter: 192.168.0.1. Select Enter or Return.
On the Arris page, create and enter a new password. (Important: This isn’t your Wi-Fi password. It’s to access to your modem’s settings.) Select Next Step.
For 2.4G and 5G, enter the same new Wi-Fi network name and password, but add 5G at the end of that network name. Write down your new Wi-Fi details for other devices. Save your changes.
Connect your first device to your new Wi-Fi network. Open a website to make sure it successfully loads.