Before upgrading, ensure that the Handy Wi-Fi connection is configured properly and you know your connection key.
Steps
Ensure your Handy is configured to correctly connect to the Wi-Fi network of your choice
While keeping the ON button pressed, unplug and then plug the Handy from its electric socket to restart it. Don’t release the button while restarting.
(The ON button is on the opposite side of the LED)
When the LED starts blinking WHITE and YELLOW, also press the UP button without releasing it.
Now release the ON button, then the UP button. If everything goes well, the LED will start blinking WHITE and BLUE. This means the upgrade is in progress.
At the end of the process, the LED will blink GREEN and YELLOW. You can now press the ON button to restart the Handy with the new firmware.