Shared Account. forgot my password.

Hi.

About a year ago I took advantage of the so-called "general account". Went at it through iCloud. Half a year ago, my iPad has been updated to 8.0. He demanded activation. I remember the Apple ID, but I do not remember the password. I have a key RK. I'm a lot of things to try. Nothing comes out. I have an email from this account.

Help !!!