The Zyxel NR5103E typically supports two primary methods for updating its firmware:

In the router interface, go to . Click Choose File and select your downloaded firmware.

Addressing system freezes that occur specifically when utilizing high-speed 5G bands, which sometimes require daily reboots on older firmware.

If you have a specific firmware file (e.g., from a service provider like Three UK), follow these steps: Download the firmware file to your computer. Firmware Upgrade menu, click Choose File to select your downloaded file.