To do this, you will need a TT Pro pre-loaded with the firmware that you need to update on the device. 

See the other knowledge-based article on how to load the firmware onto the TT Pro.  (https://aldoussystems.zohodesk.com/portal/en/kb/articles/how-to-load-device-firmware-on-the-ttpro)

The video below shows how to update the firmware on the DMBD GW.