This is how to do it:
Updating the firmware of your DwarfConnection Wireless system is easy and can be done right from your own PC*:
Connect your transmitter or receiver to your computer using the USB port. Do not forget the power supply!
Press and hold MENU on your transmitter or "+" on your receiver while turning it on.
The device will appear in the explorer.
Now copy the latest firmware file to the device and you are good to go!
Usually, the device will disconnect automatically as soon as the update is completed.
* Yes, it HAS to be a PC.