It’s not something that can be done by an end user. There are places in EU that offer this as a service but that will require some research on your part.
Posting this again (refer to attachments), as I seem to get a lot of requests for "how do I do this?":
1. If you are on a FW version below 59.x, then you need to update to version 70.x first.
2. Once you are on 59.x and higher, then you can update to the latest version (74.00.324A)
I am also...
DTC = Diagnostic Trouble Code
Basically it is an error code that the car reports back to indicate to you what the problem is.
The instructions you quoted are saying “don’t do this or your car will set a DTC and report an error, which will require you to clear the code”.
Unfortunately you cannot change regions with the new units yourself. I say that because there are some places online (I haven’t looked into it) that can change the regions for you for a fee. The older (6th) gen could be done with a simple FW change.
To be honest, I have no idea.
I was just providing a link to the OEM welcome (puddle) lights :)
Here’s some install videos (also in Japanese), but they may help: