Need 3G/GSM based Firmware upgrade for Arduino microcontrollers

You can hack it yourself using any GSM module like the Low Cost SIM800 Module and the Arduino Board. You will need to find a way of remotely resetting the Arduino during this process so that it can allows new codes to be updated.

Another way is to use the Particle Electron Board from the particle guys or use the Electric Imp board. An example of wireless firmware upgrade with the electric imp board is found at this sparkfun example .