Eeeeek! This puts you into a rather undesirable position as there is no way to truly recover a password in any Notes/Domino-based ID file as the password is not actually stored. It is used as part of the hash for decrypting the ID. What you can do is to create a new certifier and create cross-certificates with all of your servers for the new Certifier and then transition people as required.
We have extensive global experience in these migrations. If you need assistance, please feel free to contact us.
Sincerely,
--Daniel Lieber
Innovative Ideas Unlimited, Inc.
Wakefield, Massachusetts USA
DLieber@iiui.com
http://www.iiui.com