If you haven't resolved this yet, I have the necessary files (which you need to put on a USB drive) and instructions. It's quite easy, really. If you send me a gmail address, I can send you a link to the folder where I keep this information on my Google Drive. You can download it from there. Cheers.
Although I've never used it, I've just noticed that there is also a "DVD USB" folder (containing an auto-script file) which I assume is the one for the DVD region change. Like I said, I've never used it, but it's there, along with the instructions for implementing it.