Just use your handle and password to log in. If you were still level 1 however your account would have been deleted, so you should make a new one - if its level 2 or higher then it will still be around and fine for you to log back into.
He really should have been more specific. He's my brother (also my multi) and the problem he's having is that he is still listed under my account as a multi, however his password does not work. Also I believe that he was under level 2 when he left so he SHOULD no longer exist.
We're just trying it get him started without getting into trouble. :P