Try this, posted by
IB-Dick:
Can I unlink my Flyertalk and Facebook accounts?
Yes, you can. However, if you created your Flyertalk account through Facebook Connect, then you will have to update your email address first. Since Facebook doesn't send us any of your personal information, the only email address we'll have on file will be a Facebook proxy address, and after you unlink your account that won't work. Since you won't be able to log in through Facebook anymore once your account is unlinked, you'll also need to provide us with a password. As of right now, all users will be required to change their password when they unlink they're accounts, even if they didn't create their account through Facebook Connect. This is simply because we don't have the ability to tell if the password hash in the database is the hash of a real password, or a random dummy password that was generated for a Facebook user. The link to unlink your accounts is in MyFlyerTalk.