Backup Exec 2010 R3

Hi there,

We are using Symantec Backup Exec 2010 R3. OS Win Server 2003 Ent with SP2.

There are 5 Jobs running @ different timing (no time conflict please). These jobs are been taken on external drive (USB HDD of 2 terra) connected to the same server with Letter E.

My Issue:

The Hard disk is now full and all the backups are in queue as there is NO space available. The Media Set for all the jobs are set to – "KEEP DATA 4 WEEKS" with Append to Media, Overwrite......

How to overwrite the jobs??? OR How can I configure the Jobs to DELETE the old backups & keep running the new jobs.

Any help will highly appreciated.

Thanks - Muzaffar