Xbox Live changing account age problem?

I am 15 and i am using my dad's email for xbox live. I want to change the email to my main account but it says its a child account. How do i change the account's age? do i have to go on hotmail and change it there?Xbox Live changing account age problem?you cant change the age. they make you put an age then keep it so they can try to keep kids from buying M rated content on live or making changes to settings, etc. the only way to up your age is make a whole new account.