If your node boards hold it's fairly easy to update, not much different than SAM. You might need to install the previous code versions first because some of the updates had two files, one code, one Spike system. I really don't know about that for sure though. (1) download code from Stern site, unzip folder and put the file(s) that was inside of the folder onto your thumb drive. As I recall, .75 is only one final file, but as I mentioned previously, sometimes it's two files, cause Lyman had to update the Spike system at least twice recently. The file should be about 3.5 GB file size. Also, it will take a long time to download it and move it to a USB drive. (2) behind the trans light there are two USB ports side by side. I usually use the left one. No dip switches to turn. (3) as I can recall, it's about the same from that point, plug into the USB, power cycle the game and wait for the cue to hit the button inside the coin door, though the update can appear to stall for a few minutes sometimes and look stuck. In Spike, code has to propagate to the node boards, so if one goes bad it could ruin the update.
Suddenly, updating code scares me a little bit.