Xbox live help please!?

ok my little brother and i have a shared account but now our parents are getting him one cause im moving out and im taking the xbox 360 but i don't want to change my gamertag or lose all of our hard earned achievements so how can i change the age or move all of the achievements and gamertag so i can get the mature rated trailers and demosXbox live help please!?Make another Windows LIVE (hotmail) account with the age OVER 18, go to 'Account Management' in the 'Account Settings' tab (Edit profile slide on your Xbox 360), click the 'Windows LIVE ID' tab, and change e-mail to the new Windows LIVE address.Xbox live help please!?Well before you login on (same screen though) you can click on Recover Xbox Live Account, doing this will basically recover all of your achievements for your games, etc. I am not entirely sure for the age, but could be under personal settings, or you may need to try xbox.com to change it there :).