I did get the USB stick today and gave it a try. It worked!
It took about 5-7 minutes, but it worked.
You unplug the box, put in the stick and plug the box back into the electrical outlet. Up comes a yellow screen that says something like "Installing upgrade. Do not unplug.". Then it has a status bar across the screen and says things like Erasing kernel, Writing kernel and other things I can't remember.
When it was done, it said to unplug the box and remove the stick. Then when you plug it back in you go into the scan for channels. It finds them and then asks about the timezone and sets the time.
Someone earlier mentioned about the serial number going away once upgraded as a way to tell. Mine serial number was there before the upgrade but is gone after. Another thing I notice is that the USDtv symbol (swirl) is not on any of the menu pages.
One tip - my program guide was not working after the upgrade. This was becuase the box defaulted to get the time from the first channel it found. It so happens that it pulls the program guide from the time channel. My first channel is a local program and it doesn't put out the program guide. So I went back into the menu and chose to get the time from NBC and poof, my program guide works!
I am really happy about this. I did try to read the drive in my computer after I upgraded. It said the media was not formatted so I don't know what is on there.
In any case, it worked! So thank you USDTV for the box and thank you to the ebay dude named marsman5d4h for the upgrade.
Just in time for NCAA basketball tonight in HD -- go Tar Heels! Again THANK YOU USDTV for letting us keep these.