X10iUser
Android Expert
You will need to ROOT your phone to do this, and although this is to change to Global, you can use the codes for region if it has been released.
- XDA
Using root explorer I edited "build.prop" from within the system folder.
I changed
ro.semc.version.cust=xxxx-xxxx
and
ro.product.name=X10_xxxx-xxxx
I changed the xxxx-xxxx to 1235-9897 (World generic)
saved the settings and exited from the file.
I also changed the ro.semc.version.cust=xxxx-xxxx file in...
/etc/customization/settings/cust.prop
saved and exited.
Then I switched the phone off and on again..
Then off one more time..
Then I used SEUS...
It will say that you have the latest software (because you do!).. but if you do a repair then it will replace your current one with the one associated with the codes you entered...
and bingo.. job done..
CODES here.."customer location finger prints" - xda-developers
Obviously this only works with firmware that has been released into SEUS.
- XDA
Only problem is, I have moved house and don't have internet access atm (I'm using my X10 with barnacle wifi to get online) so I wont be able to update when it is released in UK. Although I could pop into the place my mother works, round the corner, and do it in there 
