If you look through the 2 stickies in here, 2def explains very thoroughly various fastboot commands to unlock, root and restore system images. They are done in a cmd window on your comp while its hooked up to your phone and the phone is in the bootloader. Fastboot commands essentially does everything odin can. On my previous samsung phones, I used odin alot and it would hang sometimes. I thought it was unreliable at times. Ever since I have owned the gnex and now the n4, I have not used odin once. Don't worry, these nexus devices are really easy to recover from a screwup. Just gotta get familiar with fastboot. Adb and fastboot are different although both of them use the cmd window.
Edit: On the gnex we could hold the volume down button and then hit the power button and we could get in download mode which then could be hooked into odin. I just tried on the n4 and that download mode is not accesible. Must be because this is an LG phone and the gnex was samsung. So it seems odin or any other exterior program won't work.