Download the firmware image from a the manugacturer. In the case of Sony, the download is an ISO image wrapped up in a self-extracting .exe file. Why is it a .exe file? It's not like it's a program that has to do some proprietary shit to talk to the BD player over USB. It's just an archive. Why not have the ISO image just plain on the site? Or in a ZIP? Guess what, geniuses: Mac has only 10% market share, but I bet if you eliminated corporate sales, it's more like 20%. And I'll bet if you surveyed people who have BD players, it's even higher.
Anyway, run Windows in your VM to extract the ISO from the .EXE. Then burn a DVD from the ISO and put it in the BD player.
Now wait while the LED display of the BD player spews out incomprehensible messages for a while. Don't bother turning on the TV, nothing will be there to indicate what the heck is going on.
After a while, the BD player will spit out the disk with another inscrutable message. Upgrade complete.
