We’ll need to open the units and do the update manually 🙁
Wish there was a way to implement OTA updates, but that’s simply not possible with the current firmware.
To update, a programmer is needed. I personally use the USPAsp. Any of these two variants will work:
http://www.ebay.com/itm/351223992863
http://www.ebay.com/itm/351223992863
Though I prefer the one with longer cable. Also it’s important they are set to 3.3V using the jumper. Using it set at 5V is dangerous for the Ethernet module in the uRADMonitor unit.