WebOS Ports posts instructions for alpha Galaxy Nexus Open webOS port 21
If you're feeling up for some time in Ubuntu's Terminal and have a spare Galaxy Nexus sitting around, then we might just have a project for you. Yes, ladies and gentlemen, you can now get an early build of Open webOS on the Samsung Galaxy Nexus running all on your own. Unless you're like us (i.e. Linux noobs), in which case you might want to hold off for a more straight-forward installation method.
The instructions posted by WebOS Ports do require some understanding of working in Terminal, or at least the ability to closely follow instructions and input the commands you're told to input. And, of course, you have to be willing to accept that this could bork your entire device and you'll have to start from scratch on all operating system fronts. Such is life on the alpha edge. The instructions come with a set of big scary warnings, which in essence can be boiled down to "you should at least have a vague idea of what you're doing and be willing to smartly ask for help". The installation process will be streamlined in the future, but for now it's not for the faint of heart. Alpha, people, alpha.
At the very minimum you're going to need to install the latest version of Ubuntu Linux (thankfully, unlike the convoluted built process for raw Open webOS OE, it doesn't matter whether you've installed a 32-bit or 64-bit version). You'll also be installing the Android SDK and unlocking the Galaxy Nexus's bootloader, in addition to downloading and building the latest version of the Open webOS port (a process that even in our virtualized Ubuntu machine with two Intel Core i7 cores and 4GB of RAM took less than three hours).
Build instructions for the Galaxy Nexus Open webOS port are located at www.webos-ports.org/wiki/Galaxy_Nexus_Build_Setup
Installation instructions can be found at www.webos-ports.org/wiki/Testing_Gnex
It's worth noting that even once the installation process is done, you're not going to have an Open webOS smartphone. There are still a lot of bit hurdles the WebOS Ports team is going to have to overcome. This build also ins't exactly portable - it's still reliant on files located on your computer. It's still an early alpha, so don't expect miracles. And have some patience too. If you're Linux noobs like we are, you'll need it.
Source: WebOS Ports (Twitter)