I have two icloud emails and need help getting rid of one.

I use a current icloud account and my apple id takes me there, however I keep getting notices about an old icloud account and I am trying to access, and cannot. I don't know the password for my old icloud email which I cannot access to validate the email that Apple sends in order to receive the notification to change my password on it, so it puts me in a loop. Any ideas? Thanks.