Xbox LIVE now allows user region migration
Transfer your account to another country without involving support
Microsoft has announced they now offer user-initiated Xbox LIVE Account Region Migration.
If you have moved to a different Xbox LIVE region, you can now move your account and take your gamerscore, unlocked achievements, any Microsoft Points already in your account and any remaining time on your Gold membership. You can do this by going to the Account migration page on Xbox.com.
Of course, due to regional differences, when you change the region of your Xbox LIVE account, some things are potentially affected, such as subscriptions, Licensed digital content (like games, video, and music) that you’ve already bought, and services you get through your Xbox console.
In the past, moving your account required a call to Microsoft technical support and a manual transition process.