If they are going to a PST file, you can open the file by (in outlook) file>open > Outlook data file and browsing to it. delete what you need and disconnect. Move to the next user. Something to Keep in mind is that a PST file has limitations and if it ges too big, it can become currupt. I would periodically rename the file and let outlook recreate it. As well as train the users to open the rename file.