Change Autoreply in Users Outlook/Exchange 2003

How to get at an autoreply in someones Exchange email and edit it?

Scenario – staffer has put autoreply on her email that she thought was perfectly suitable.
Staffer is now in maternity delivery room yelling and straining in the throes of delivery – arent women the lucky ones!
Staffers boss deems autoreply to be unsuitable.
Boss logs job with exchange admin to change autoreply.
Whereas with a public folder its no problem how do I get at the staffers email settings to edit their autoreply?
Have given myself rights to staffers mailbox but this does not give me access to their Outlook settings.
Have Exchange Admin rights.