The Google Galaxy Nexus which was sold through the Google Play Store is known as the ‘takju’ version. If you own one of these devices you can manually update it to the latest version of Android 4.2 Jelly Bean which is version 4.2.1. You can optionally wait for the update to be made available for your device and opt for the automatic update, but we are certain there are some of you who may prefer the manual method.
The process of manually updating should work long as you have flashed the ‘takju’ factory image on your device.[NOTE] We do not recommend that you proceed unless you are aware of the risks. Your device may malfunction or you may loose data from improper use of this guide.
[NOTE] In order for these updates to install, you need at least one of the following: an unlocked bootloader OR a custom recovery OR root.
- Download the correct version of Android 4.2.1 Jelly Bean for your device.
- Copy the downloaded file into /sdcard on your device
Stock Recovery, Unlocked Bootloader
- Download CWM from here and place it on your computer in the same directory as your fastboot binary. For CDMA/LTE devices, use this version;
- Rename the CWM image to cwm.img
- Reboot into fastboot mode;
- Open a command prompt in the same directory;
- Type fastboot devices to make sure your device is recognized;
- Type fastboot boot cwm.img
- Select "install zip from sdcard";
- Select "choose zip from sdcard";
- Select the update the you just copied to your device;
- Wait until it completes. Reboot. Done.
Custom Recovery
- Reboot into CWM;
- Select "install zip from sdcard";
- Select "choose zip from sdcard";
- Select the update the you just copied to your device;
- Wait until it completes. Reboot. Done.
If you have any questions of issues we suggest that you head over to the source link. If you don’t feel safe following this guide we suggest waiting until the update is made available for your device through the Software Updates under settings.
source – XDA Developers | Android Central