Galaxy Nexus i9250 Gets Jelly Bean with CyanogenMod 10 Nightly ROM [How to Install]
Photo: XDA Developers

A CyanogenMod 10 based Android 4.1 Jelly Bean update is currently under development for the Galaxy Nexus smartphone. The firmware update is still in its early stages, but experienced users can get a taste of the latest Jelly Bean updates based on CM10 ROM with nightly build releases.

Thanks to XDA senior member, erezak, the unofficial nightly build of CM10-based Jelly Bean for Galaxy Nexus is now available.

Requirements

  • The ROM and the instructions in this guide are meant for the international GSM version of Galaxy Nexus with model number i9250 only. It will not work with US variants or any other device. You may verify your device's model number by navigating to Settings > About phone.
  • IBTimes UK advises users to back up important personal data (bookmarks, contacts, SMS, MMS, APNs and other internet settings) including contents of the SD card to avoid data loss while performing the Jelly Bean update.
  • It is necessary to unlock the bootloader and install TWRP or ClockworkMod (CWM) recovery on your phone before trying to install the CM10 nightly ROM-based Jelly Bean update on it. Failing to do this may cause irreparable damage to the unit.
  • The procedure given in this guide is meant for reference purpose only and does not cover any warranty claims involving device damage or issues arising out of using this firmware update.

How to Install CM10 nightly ROM-Based Jelly Bean Update on Galaxy Nexus

Step 1: Download the latest version of CM10 Nightly ROM from XDA Developers official thread (Download here).

Step 2: Download the Google Apps package from here.

Step 3: Without extracting, copy the two downloaded zip files in step 1 and 2 to the phone.

Step 4: Power off the phone and boot into TWRP/CWM recovery using a button sequence. Press and hold the Volume Up, Volume Down and Power buttons together until the screen powers on. Now, using the Volume buttons, navigate to the Recovery mode option and then select it using the Power button to reboot into recovery.

Step 5: Now, tap Backup and then slide the blue circle button at the bottom to the right to initiate back up process for your current ROM. Using this backup, you could later restore your original ROM if something goes wrong with the newer ROM. Once backup is done, return to the main menu by tapping the home button at the bottom left of the screen.

Step 6: Hit Wipe, and then choose Factory Reset. Then, tap Yes to confirm data wipe on the next screen. It must be noted that this procedure will NOT wipe the contents of your internal SD card. So, you can leave it connected to your phone. Now, return to the main menu by tapping the home button after wipe is complete.

Step 7: Click Install, then locate and choose the ROM file you downloaded in step 1 above. Confirm installation to flash it.

Step 8: Once the ROM is installed, repeat step 7, but now choose the gapps-jb-20120726-signed.zip file to flash the Google apps package. Confirm by choosing Yes again to complete the Gapps installation.

Step 9: After Google apps is installed successfully, tap Reboot system now button to reboot and boot up the phone into CM10 ROM. The first boot is usually time consuming and will take about 5 to 7 minutes.
NOTE: In case you want to restore your previous ROM, boot into recovery, choose Restore, then restore your previous ROM by selecting it from the list.

Step 10: Updating to newer nightly updates: To update to latest versions, just download the nightly ROM, copy it to SD card, reboot to recovery, install the ROM and reboot again. You don't have to wipe data or install the Google apps package every time while updating to a newer version.

The nightly CM10 ROM-based on Android 4.1 Jelly Bean is now installed on your Galaxy Nexus.

[Source: The Android Soul]