Self Recovery of Unix Files

How can I recover a deleted file?

Faculty and Grads can recover deleted files by logging into compserv and cd to /backup/[facfs1 stufs1]/<day of month> and pickup files modified the previous day. Day "0" is a full backup for even numbered months and day "1" is a full backup from odd numbered months. The file system is read-only and cannot be used as extra storage.