I upgraded Samsung Galaxy Nexus (Fido) to ICS 4.1 and unlocked it on the way along with “rooted”. 4.1 is beautiful, its fast, save on battery ceven with GPS turn on, and a lot of improvements compared to 4.0.2, and gives you a great feeling. The process is a bit complicated and time consuming but is really worth it.
First you need to install the Nexus Tool Kit
Then follow the instructions on:
[All credit goes to my friend Umar Q.]
Note that this process is switching your Samsung Galaxy Nexus from Samsung’s android (which has no updates) to Google’s android (which has current version of 4.1.1). The procedure actually updates the phone to Google Android 4.0.4. Once done, you can do the OTA (over the air) upgrade using your phone. This makes Galaxy Nexus upgraded to Adroid OS 4.1.1 also known as Jelly Beans. Not to mention, i don’t like Jelly Beans
Disclaimer: Please do it on your own risk. Writer of this post or anyone else for that purpose will not be held responsible if you brick or damage your phone during this process.