Apologies if this question has been asked (and answered) many times before, but I can't seem to find a satisfactory answer.
My company changed to a new LDAP directory server, and the old users where not mapped across. Usernames were changed too as part of the update (so, for example, johnd became jdoe). Unfortunately, since the old LDAP server no long exists, we now have tons of projects with invalid project leads and issues that have been reported, assigned to and commented upon by users that no longer exist.
Is there any easy way to remap an old LDAP user to a new LDAP user across the whole system (group memberships, project leads, reporters, assignees, commenters, etc.)?