How to retrieve Outlook Express pwd?

is there a way to retrieve or disabled the Identity Password in outlook express if no one knows the password? i hv a few identities which is protected by password but the user is no longer working in my company, how do i delete their identities if it’s password protected? and another more ridiculous situation is that one of my managers told me he cant open his email anymore cos it’s password protected. he sweared that he didnt put any password thingy into it (but i think mostly he has forgotten the pwd he set). so, now how do i unlock his email in outlook express? he is working on a WinXP pc.