I'm a bit confused, no GUI you say but then you talk about sidebar. Do you
mean on another computer?
You'll want to use the -r parameter for "recursive". And then you need to
specify /full/path/to/where/you/mounted/that/disk/
The easiest way is to use a live CD or USB to do the job.
And if you have a separate /home partition (can't remember whether there is
one by default) you might not even need to backup before reinstall, just
choose another username. Having said that, now is always a great time to make
backups.
