There are two ways you can accomplish this, one is by following the instructions relating to your operating system in the following thread:
FAQ: How to Delete Backups
http://social.microsoft.com/Forums/en-US/onecarebackupandrestore/thread/f0281206-ed0b-474c-8541-cc50843e5be2The other can be used if you have either no or only a few other files on the external disk. Simply copy any files you wish to keep temporarily to a folder on another drive. Once you are certain that all important files have been copied, simply format the external drive to wipe out everything including the OneCare backup. Of course, this will only work if you have enough disk space on other drive(s) to copy the files you need to keep.
< EDIT > I have moved your post to the Backup and Restore forum since that's what it discusses.
OneCareBear
Windows OneCare Forum Moderator
