How can I change a child account to an adult account.

I can't remember 100% but I am sure whoever set up the child account can change it. Like if you made an adult account on the xbox before making the child account that adult account can change wether the child account is a child account or and adult one.
I will just test this out myself now and post how it went

How to change child account to an adult account

You can change a child account to an adult account, but you can't change an adult account to a child account. In order to manage them, you would have to create new child accounts for them.

[quote user="ArkticZenith"]

I know but I was wondering with the new dashboard update coming soon maybe they will change it so you can change your age or promote to adult account.

[/quote]Why should they let you change your age? Can you change your age in real life?

As for promoting to an adult account. You can promote a child account to an adult account if you are an adult, not a child pretending to be an adult. http://support.xbox.com/en-us/xbox-live/how-to/online-safety

[quote user="TiedSilver596"]How do I change my account from an adult to a child?[/quote]

You are trying to change an adult account to a child account? While the age of the account is determined by the DOB on said account, we can change the privacy settings for this account to have child-like privileges.
To do this, just navigate to Settings>Privacy & online safety>and make the appropriate changes their.

Let us know how that goes, or if you have anymore questions.