How to remove your Classmates account
Use the link, give a reason why to quit and off you go. Also read http://www.classmates.com/search/help/article?articleId=4384
Direct removal link: https://secure.classmates.com/auth/removemember
Helpful Trick: Removing online data
Helpful Trick: Remove third-party logins
If you signed up for Classmates using a third-party login such as Facebook or Twitter, you probably want to revoke all access from Classmates. Click here to find out how.