how to recover icloud passward

I have forgot the passward of Icoud of my Ipad and even i did not remember by secret answer. my apple id is different than icloud id .....my apple id passward works on Itune but not on icloud.....i have tried to sign out the icloud but turning off the "find my ipad" but it ask me for the passward of my Apple iD and when i use that it shows invalid and the same passward works on itune....Is there any other way to logout from icloud?