Please tell me Google are that stupid? :/
Steps:
1. Send an Adsense request
2. You will receive an email telling you your under age
3.Then it should have a link in the email to change your age
4. Next go ahead and scan your drivers license and click submit
5. Now you have changed your age!
http://www.google.com/adsense/support/as/bin/request.py?contact_type=under_age
But yeah a lot of things say you cant, dont know if thats a work around
شكرًا على الاتصال بنا. لقد صححنا تاريخ ميلادك في حسابك في Google.
ويمكنك إعادة إرسال طلب اشتراكك في AdSense الآن على الرابط https://www.google.com/adsense.
نشكرك على حسن تعاونك.
مع فائق التقدير،
فريق Google AdSense
Translation:
Thank you for contacting us. We rectified your birth date in your account on Google.
You can resend your subscription request in AdSense now is the link https://www.google.com/adsense.
Thank you for your cooperation.
Sincerely,
The Google AdSense Team
Bizarrely, they sent me an email in Arabic that got picked up as junk