Restricted Access Files, Backup and Restore

Top of the evening,

I'm having the graphics card on my Macbook Pro 2011 replaced, but they need me to backup the hard drive first, in case they wipe it in the process. They offered to do it for me, for $280, but I hoped I could save some money by doing it myself.

I can access the main hard drive through my office network, and can copy the files off of it for the backup, but some of the (most important!!) files are on my wife's username, and are thus restricted, with the little red circles on them. I can't change permissions or enter my admin password through the network, so I can't access them.

Does anyone have any solutions or suggestions as to how I might remedy this issue?

I apologize if there is already good information on this; I wasn't able to find it after a pretty extensive search.

I sincerely appreciate your help,

Nik