If you mean fanpop accounts. They should give you an option before you log in via using your email to recover accounts or passwords. If not that's basically how you do it. You use an email and then the site then sends you your account name and/or password or gives you an option to change your password.
You can go to the main Fanpop tahanan page and there'll be an option on somewhere near the bottom which gives you the option to contact Fanpop. You can use this feature email them and ask if you can get your account back. Don't hold your breath though... it's not likely to be recovered.