Resetting iCloud passcode after restoring iPad using iTunes

I have forgotten the passcode. My IPad was locked. I have restore it using iTunes. However, iCloud will not sync untill I put the passcode that I cannot remember. How do I reset the iClou passcode. I do have the email an passwor used for iClou.

[Re-Titled by Moderator]

Original Title: Reset iCloud Passcode