Restriction Passcode
How do I reset Restrictions Password?
iPad 2, iOS 7.0.4
Normally you have to perform a reset as a new device, losing all data when forgetting the restrictions passcode. Or, restore from a backup made prior to enabling restrictions. However this might give you some ideas:
http://www.iphonebackupextractor.com/blog/2013/apr/24/reset-ipad-iphone-restrict ions-passcode/