Two Backup files on My Passport?

I just found an Old Backup file and a New Backup file on My Passport.  How can I clear the whole Passport and start over?  I have posted this before but I have never received an answer.  Thank you.

Hello,

On this case i recommend reformatting the device, however this will erase everything from the drive but, if you wish to clear the whole passport you can do this, here is a link that might help with this process:

http://wdc.custhelp.com/app/answers/detail/a_id/3865