Summarized from another one of my posts:
You can
pay for a utility that will do this from
here or use an open source linux utility from
here. You run a risk attempting to use these utilities...the second utility, the freebie, requires a user who:
1. Can follow directions that are fairly technical/complex.
2. Has a basic understanding of Linux.
I am by no means a Linux guru yet I have used this utility numerous times - word to the wise should you try the free utility, it tends to break very important files in the OS so use it at your own risk! Good luck!