For those that are wondering, here are my brief instructions for installing ChromiumOS onto the Elitebook.
Arnold The Bat - latest special build (x86 or x64)
http://arnoldthebat.co.uk/wordpress/chromium-os/
Burn to flash drive or hdd per his instructions:
Linux:
Extract with p7zip
burn to drive using:
dd if=ChromeOS.img of=/dev/sdX bs=4M
Windows:
extract using 7zip
burn to drive using https://launchpad.net/win32-image-writer/
Boot
Go into chros shell with:
Ctrl + Alt + F2
Username is chronos
password is password
Install OS:
/usr/sbin/./chromeos-install --dst /dev/sda