Changing usernames and passwords

This is about Adobe Digital Editions. I have multiple accounts with different usernames and passwords. I don't remember any of them. I contacted Adobe and they reset my username and password. Now I have one. However, I don't know how to change the usernames or passwords on my computers at home and at work so they have the correct usernames and passwords. Right now, I can't access anything I saved under ADE. Any advice?