Backup Exec DLO Quota and Cleanup

We have a DLO user who has reached the imposed size limit on their network storage location.  Revisions are enabled in our settings.

What is the easiest way to clean up their data so that backups can continute to run? 

There is no obvious way to remove old revisions from within the admin GUI.  It's also very difficult to show which files are taking up the most space.

Any help you can provide would be appreciated.