The procedure that I followed: (best that i can remember)
1 Have a USB without any files on it, at least 8G ( the nav updates that i downloaded were 3.4 G)
2 Press the trip button to get the electric going on the bike.
3 Turn on the Infotainment system, it boots, accept screen goes away now automatically.
4 Inserted the USB
5 Setup
6 System Info
7 Navigation
8 Exp for Update
9 Select the USB
This was the process to get the finger print, i was amazed it took 2 to 3 minutes.
Then brought the USB in the house, went to the HD Navi web site and logged in
Opened the Naaviextras software on my computer
Had to log in, in my software.
It said i did not have a device plugged in.
I plugged the USB into the computer.
It said there was an important update, (this was Navi extras software update) I clicked to update the software
Then I think it said an update (maps) was available, and i clicked Install.
2.5 hours later the software was downloaded to the USB.
In the morning, I again went to the bike pressed the trip meter for power
Turned on the Infotainment system
After it booted i loaded the USB
It recognized it and asked if I wanted to update
I think i then clicked OK
About an hour and twenty minutes later it had finished updating the Nav on the bike.
Reference the number of files on the USB: I honestly don't recall, there may have been 3, but as long as there were no files when you started the process it should not be an issue because you are not moving/copying or anything to the files. The infotainment will recognize what it needs and install the update.
If it is missing a file or some other download issue exists then you would have to delete the files and do the finger print and download again.