In order to backup the documents you want I would personally try this before getting too down and dirty with the Terminal.<div><br></div><div><ul><li>Boot live CD</li><li>Insert the drive you'll backup to and check it mounts ok</li>
<li>Open terminal and enter "gksudo nautilus" without the quotes</li><li>The file browser should come up (nautilus) and be using root permissions</li><li>browse to your files you want to back up and copy to the backup drive</li>
</ul><div>Worth a try, I used to use this method to edit menu.lst without any hassle, hopefully it'll work for the files you want to backup</div></div>