First thing first, if you haven't done so yet, reveal Developer options in settings, enable USB debugging, unlock your bootloader and install or update adb, fastboot and other tools. I've written posts about that in the past, so follow the links if you need a walkthrough.
Download the latest ClockworkMod Recovery image for Galaxy Nexus (GSM) from ClockworkMod site, at the moment it's
recovery-clockwork-touch-18.104.22.168-maguro.imgand save it as
cwm.imgin your home directory.
Download the latest SuperSU CWM installable ZIP using the link in the XDA-Developers forum thread (
UPDATE-SuperSU-v1.45.zipat the time of this writing) and save it in the same directory as CWM Recovery image.
adbis detecting your devices correctly and is displaying phone's serial number when you run:
You should see similar output in the terminal:
List of devices attached 0149AXXXXXXXXXXXX device
Push the SuperSU installer to your sdcard with command:
adb push UPDATE-SuperSU-v1.45.zip /sdcard/
Reboot into bootloader with command:
fastbootis also detecting your device and is displaying phone's serial number when you run:
Boot into CWM recovery using cwm.img file in your home directory:
fastboot boot cwm.img
You will see the following output in the terminal:
downloading 'boot.img'... OKAY [ 0.707s] booting... OKAY [ 0.388s] finished. total time: 1.096s
Device will boot in to CWM recovery and present you with various options. Choose install zip option, then chose zip from sdcard, then 0/ - this is the default path to internal sdcard, then find and select the UPDATE-SuperSU-v1.45.zip file we pushed earlier. Chose Yes - Install UPDATE-SuperSU-v1.45.zip when presented with confirmation dialog and SuperSU will be installed from sdcard.
Once installation is complete select +++++Go Back+++++, then reboot system now. I personally choose not to disable recovery flash when presented with the next prompt.
Once the phone has restarted test for presence of root prompt (
adb shell su
You might want to update the SuperSU app via GooglePlay if you're not using the latest version, and it's done.