This is the wrong place to be asking about this. You should be asking
this question of the people at http://freedns.afraid.org
I would say "unlock" is the wrong word. What you want is to login to
an existing account at their website. Like it says to recover your
account ID and or password you need to know the email address used to
sign up with. If you dont know it or can not guess it then you are SOL.
You could alway contact them and ask for help.