If you call toshiba directly and explain to them that you are looking for a firmware update, they will ship you one out via sd card. It is very easily upgraded once you recieve the card.
Simply turn the tv on.
insert the card in the sd slot on the front of the tv
Upgrade process automatically begins when the card is entered , just make sure that the power is not shut off, when the upgrade process is done, the tv will restart, the led on the front of the tv will flash green while the firmware finishes updating.
Once the green led stops flashing and is solid green you can turn on the tv, once you get a picture turn back off the tv, and unplug for a minute and then completed the hard reset by plugging in the tv and turning it back on.
To double check and make sure that you have the correct versioin you can go under the installation menu and go over to information and the current version from april of 2007 is 1.6.5 I beleive!
Best of luck, I did mine a while back, but that is all that I needed to do!
I love my 57H94, It is the best RPTV I have ever laid eyes on!
- Matt