How to install Ubuntu on a CR-48 Chromebook? [duplicate]

A few weeks ago my chromebook got crazy and its OS got corrupted for an unknown reason. I'd like to instal Ubuntu 12.04 64bit on it using a bootable USB pendrive, but since it is not the usual installation that I am used to on PCs/laptops....I am a bit stuck and dont even know where to start. I'd simply like to make a pendrive that I can make bootable for my chromebook and do the installation.

There are two ways - one requires the Chrome OS to be present and utilizes the kernel there, but you can't do it from a bootable USB stick. The other way involves flashing a new BIOS - but again, you have to be in a workable Chrome OS session. I think the BIOS flash tool got pulled by its creator and is hard to find. But either way, you will need to restore Chrome OS. There is a recovery to do this -

Recover to stock cr48

Once its recovered, just google for the cr48 BIOS to install from a pen drive - good luck.