[Update: With Root] How-to: Upgrade To Android 4.2 Jelly Bean On Your Galaxy Nexus

 Galaxy Nexus 4.2 Jelly Bean

Alright, I didn’t have the time to post this, but since many of you Galaxy Nexus owners out there might want to be up-to-date with the latest version of Android, v4.2 Jelly Bean, like me, here’s a small tutorial for you.

First things first, neither I, nor Androsym, take the responsibility for any damage or natural calamity which might result after following this tutorial. However, succeeding in upgrading and rooting after following this tutorial might result in never-ending happiness.


With that out of the way, let’s begin!

  1. If you’re already running a “takju” build of Android 4.1.2, it’s easy. Otherwise, download the Takju 4.1.2 Factory Image from here(you can flash Takju even if you’re running Yakju, that’s what I’d done, too.) It’s about 240 MB in size, just so you know. However, there’s another method, which is a wee bit easier.
  2. Download Galaxy Nexus Toolkit v9.1 from hereFor sanity, I’m going to assume it installed properly, and that it can detect your device. If not, this XDA thread is there for your perusal.
  3. Select the appropriate option when it asks you to select your build. It should be option number 10 (Takju 4.1.2).
  4. Next, you’ll want to select option number 9 – to download, extract and flash the stock image from Google. If you’ve downloaded the Takju 4.1.2 Factory Image from the link above, select option 2, otherwise 1.
  5. Let the toolkit do its work, and select the appropriate options when asked.

So now you’re running Takju 4.1.2 on your Galaxy Nexus. You’re all set to follow the next set of instructions.

  1. In the toolkit, select option number 4 – Root or Unroot. Now, select option number 2 – Root phone + Install Busybox. Again, follow appropriate options from here – the toolkit will hold your hand and guide you.
  2. Your device has now been rooted. You’ll need to flash a custom recovery now.
  3. Again, in the toolkit, select option 6 – Flash recovery. I advice you flash TWRP Recovery, since the CWM Recovery that the toolkit has, is broken. So select option 2 and follow the instructions.
  4. Now that you have a rooted 4.1.2 Takju ROM and a custom recovery, download the official 4.2 OTA File from here. Rename it to “Update” (on your PC), and place it in the root of your Galaxy Nexus’ internal memory.
  5. Disconnect the device from the PC. Power off the device, and hold both Volume Up and Down simultaneously. Press the power button at the same time until the device goes into Fastboot mode. From there, use Volume down button and press the power button when you see “Recovery”.
  6. After booting into recovery, select “Install Zip” and select the “Update.zip” file. Follow the instructions.
  7. It will take a few minutes for the zip to be installed. Once it says that the installation has completed, select reboot device.
  8. Viola! You’re now running Android 4.2 Jelly Bean.

Update: Finally rooted the damn thing.

  1. Select the correct option (for your build number) in the toolkit, and in the Main menu, select option number 8 and follow the instructions.
  2. Download Supersu 0.97 from here and place it in the internal memory.
  3. In the toolkit, select option 22, Reboot Options, select reboot into recovery.
  4. On your phone, select install zip and flash Supersu 0.97.

Aaaaaand, you’re rooted. Enjoy.

I haven’t yet been able to root the device on 4.2, so yeah, that’s one thing to keep in mind.

If this tutorial helped you, please share 🙂 If not, post a comment and I’ll see if I can help.