How to login to or view root-owned files on a broken linux install from a Kubuntu livecd

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http://unix.stackexchange.com – I seem to have broken my Kubuntu 12.04 64-bit installation after black screen and hard shutdown (running Gnome 3) when my computer attempted to go to sleep and I shook the mouse. I recently installed the official drivers for my Radeon 6850 and they seemed to be working peachy. After the crash my BIOS seemed to show longer than usual so I turned off overclocking on my CPU and RAM to see if these may have caused system instability, although I've been overclocked since before I started using Linux. When I tried rebooting, errors indicated that USB devices weren't being recognized properly, so (HowTos)