CF-Root tool has been released for the Galaxy Nexus by Chainfire, Android developer and hacker, CF-Root released to root the device on Android 4.0.2 Ice Cream Sandwich, now we are going to show you simply how to root your Galaxy Nexus on Android 4.0.2 Ice Cream Sandwich after the jump!
This rooted kernel is for the “rooting beginners” and those who want to keep as close to stock as possible. CF-Root takes the kernel from an original firmware, and just adds root and busybox.
How To Root Galaxy Nexus On Android 4.0.2 Ice Cream Sandwich
First you should download CF-Root (GSM) [Build: ICL53F], CF-Root (LTE) [Build: ICL53F], for Galaxy Nexus.
You can check which version you should download by going to Settings > About phone and observing the build number.
Ensure that your device is not connected to your computer.
Step 1: Download and install ODIN version 1.85[XDA Thread].
Click on PDA and select CF-Root-xxx-vX.X.tar
Step 2: Turn off your Galaxy Nexus, once it’s off, press and hold Volume Down + Power buttons to boot into download mode.
Once in download mode, connect your Galaxy Nexus with your computer.
Step 3: Now make sure that you have not checked the Re-Partition option.
Now click on START and wait for your device to reboot.
After doing so CORRECTLY, sure your Galaxy Nexus will be rooted on Android 4.0.2 Ice Cream Sandwich.
Quick guide (for experienced users)
– Reboot into download mode
– Using the attached Odin version, flash the attached XWKDD kernel as PDA. Do not use the PIT, do not have any options checked except for “Auto reboot” and “F. Reset Time”
– Wait for the device to reboot
– Use the “adb root” command to restart ADB in root mode, followed by “adb shell” to get a rooted shell; then you can manually push Superuser.apk / su, busybox, OR use SuperOneClick to finish the job for you.
Long guide (for beginners)
– Download the attached ODIN file and extract the .zip file
– Download the attached XWKDD, but do NOT extract the .tar file
– Download and extract SuperOneClick
– If you do not have Samsung’s KIES 2.0 installed, download and install it. You need it to install the correct USB drivers, so the programs can communicate with the device. Reboot your computer after installation of KIES.
– Make sure your device is in USB debugging mode: Settings -> Applications -> Development -> USB debugging
– Reboot your device into download mode: Turn the device off, then power it on again by pressing and holding VolumeDown + Home + Power simultaneously. You will know when you are in download mode, it is really obvious 
– Start ODIN
– Connect the device to your computer using USB
– Wait a few seconds, the ODIN screen should show you that a device is now connected
– Make sure that in ODIN NOTHING is checked, except the “Auto reboot” and “F. Reset Time” checkboxes. Press the “PDA” button, and select the “XWKDD_insecure.tar” file.
– Press “Start”. ODIN you should now be flashing the kernel, and the device should reboot.
– Wait until the device is rebooted, and while still being connected over USB, start SuperOneClick, and press ROOT.
– Reboot the device
– Done !