I had an issue with my Time Machine backups when I upgraded to Mavericks. Essentially my Time Machine would no longer make backups so I decided to send all my old backups to the trash and create a brand new initial backup. When I try to Empty Trash with the old backups in it I keep getting an alert asking if I want to get rid of "Locked items". I always choose to get rid of everything, have even tried "secure trash empty" but still doesn't remove these files. I'm to the point now that I plan to move all of my other data (files, movies etc.) on to a different HD and want to completely wipe the one with the the 'stuck' backups on it. How do I go about wiping this HD clean?