As we have already seen, Jelly Bean ROMs are appearing for a wide range of Android devices now. At the time of writing, most are based on the Android Open Source Project (AOSP) version of Android, which is the full, bare- bones build that you will find on the Galaxy Nexus.
When manufacturers start rolling out the various updates for their own handsets they won’t be based on AOSP, but instead they will come with their very own unique skins, such as Touch Wiz on the Galaxy S Ill or Sense on the HTC One X. After this time, custom ROM’s will emerge that will include the benefits of these skins as well, but will also be optimized for certain performance factors, such as battery life or speed.
However, for many, updating to Jelly Bean via a custom ROM will be to get the benefits of AOSP — stripped back, fast and lean, with none of the bloat or unwanted features that you will find elsewhere.
In this tutorial we will be flashing Jelly Bean to a Samsung Galaxy S III, however, the process we’re using will be the same, as you will find, no matter which device you have. We’re flashing via Clockwork Mod Recovery, which will have been installed when you rooted your phone, and which you can access
by holding down a certain combination of keys when you boot — it’s often the power and volume down keys, but check online for the instructions for your specific handset.
1: Backup! Backup!
You’ll need to wipe your phone completely, so download Titanium Backup from the Google Play store_ Tap the tick icon in the top-right corner of the app and select the Backup all user apps + system data option. This will create a full backup of your phone’s contents.
2: Find a ROM
Find a Jelly Bean ROM to flash. Go to forum.xda-developers. corn and locate the right forum. Find a ROM labelled JB or 4.1.1 and download. We’re using Super Nexus, a Galaxy Nexus- style ROM. The Google apps must be downloaded separately
3: Copy to card
Copy the ROM to your memory card by connecting your phone to your computer and dragging the ROM into the window for your card. The ROM will be in the form of a zip file, but don’t unzip it. You can download ROMs directly on your phone as well
4: Recovery Mode
Shut down your phone and reboot into Recovery Mode. This process will be different depending on which device you use. Work through the menus using the volume keys to go up and down and the power or home keys to select.
5: Backup! (again)
This time we’re creating a Android backup, which produces a snapshot of your system, including the apps, data and OS. You can restore your phone from this in future. Go to Backup and restore>Backup and it will start straight away.
6: Clear your data
From the main Recovery menu you see select wipe data/factory reset. Scroll down a few times to confirm the choice, then your phone will begin resetting. It won’t affect your external memory card, so your data backup and Android backup will be safe if you need to restore them.
7: Ready to go
You’re ready to flash the ROM. Select install zip from sdcard and then pick the location where you saved the ROM — either choose zip from sdcard or choose zip from internal sdcard. Scroll down to the ROM, and keep scrolling if it’s not on the first page.
When you click on the ROM, scroll down to Yes to confirm the installation, or click on Back to abort. The process will start immediately and take a few minutes. Keep your phone plugged in, and don’t interrupt the process until it’s finished.
When the process completes you must reboot. The first boot with a new ROM can take longer than normal. Once the phone has restarted you will see the familiar Android setup screen. Fill in the details for your Wi-Fl connection and Google account
10: Restore backup
You may need to flash the Google apps separately through the same procedure as in steps 6 and 7. Now restore your data and apps. Install Titanium Backup from the Play store, tap on that tick icon and select the option to Restore your apps and data.