I was able to update my L900 with this method. But it took a while, the timing is fussy and not obvious. In my case the difficult part was turning off the WiFi fast enough as its under software control no physical switch. Take your time, try modifying how you carry out each step, and it will work. Note that you may have to install several updates in sequence to get this to work.
Overall it took me about 35 min to get the first update to happen, but after that I had the magic timing right for my laptop and all three updates went smoothly. The while process took about an hour once I got the timing right as there were three updates to download and install.
Patience Padawan! You will succeed!
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