Dunno about the TV. But my Humax Freeview STB has serial connection which can be used for uploading firmware upgrades from PC (after first downloading from Internet). Although the upgrades are available over the air, they are available sooner off the Internet.
For this to work, one requires (for my box) what is known as a Null Modem Cable (and, of course, a serial connection on your PC). Cables avaialble on ebay, maplin etc.
If you haven't got a serial connection on your PC, you can get a USB to serial adapter.
It should all be described in your manual.
Maybe the TV can take firmware upgrades in a similar way.