Verizon began rolling out Android 4.1.1 Jelly Bean firmware for Galaxy S3 SCH-I535 recently, but you can go one step ahead with a custom firmware build and install the latest Android 4.2.1 Jelly Bean on your Samsung smartphone. You will be required to install custom firmware LiquidSmooth ROM, which is based on Android 4.2.1 Jelly Bean AOSP to upgrade to Android 4.2.1 Jelly Bean on the Verizon Galaxy S3.

The LiquidSmooth ROM is said to be one of the smoothest, most stable and fastest ROM as it is built from AOSP release. The ROM carries a bunch of customizations that you often find in CM10.1, AOKP, Team CAN and Team EOS ROM, Android Jinn reported. The report further states that though most of its features work fine, users may still face some issues and bugs while using LiquidSmooth ROM on Galaxy S3 I535 as the ROM is still under development. However, all these issues are expected to be fixed in a while as development progresses.

Below is the step-by-step tutorial to install Android 4.2.1 Jelly Bean on Verizon Samsung Galaxy S3 I535 using custom firmware LiquidSmooth ROM. This is an exclusive tutorial for Verizon Galaxy S3, model number SCH-I535. Don't try this guide in any other Android device. You can check your device's model number in: Settings » About phone. The users must note that IBTimes cannot be held responsible if anything goes wrong. Proceed at your own risk. Before you get into it, there are some prerequisites that you should be aware of:

1. Backup your data so that you can recover in case you lose any. The below mentioned instructions will help you make a backup.

-   SMS & Call Log - Use SMS, MMS & Call Log Entries Backup & Restore App
-  Contacts & Settings - Use Android default backup options.
-  Images, Songs, Videos, Files - Have a copy in internal or external SD card.
-   APN and MMS Settings - Note down from the path "Applications > Settings > Wireless and Network > Mobile Networks > Access Point Names"

2. Make sure your device has at least 80 percent battery power.

3. Backup your EFS Folder. [Guide]

4. You should have a USB drive installed for Samsung Galaxy S3 in your PC.

5. Make sure USB Debugging is enabled.

6. Make sure that your device is rooted and has ClockworkMod Recovery Installed.

7. Make sure you don't skip Nandroid backup as it's very helpful if this custom ROM doesn't work the way you wanted.

Required Files are:

- LiquidSmooth ROM For Verizon Galaxy S3 [Filename: Liquid-JB-v2.1-Beta1-d2vzw.zip]

- Google Apps [Filename: gapps-jb-20121011-signed.zip]

Once the above requirements are met, you are all set to install Jelly Bean based LiquidSmooth ROM on Verizon Galaxy S3 I535. The steps are:

Step 1: Connect your Verizon Samsung Galaxy S3 to PC via USB.

Step 2: Copy all downloaded zip files to the SD card of your device. Don't extract any file.

Step 3: Disconnect USB and turn off your phone.

Step 4: Boot into ClockworkMod recovery in your Galaxy S3. You can do that by pressing and holding Volume Up, Home and Power button together till you see Samsung logo on screen. Release all three buttons and you will see ClockworkMod recovery screen. Use Volume keys to browse between options in recovery while using Power key to select an option. (You can also try this alternative method to achieve Recovery Mode without key combination)

Step 5: Perform a Nandroid backup of your existing ROM. It can be done by selecting Backup and Restore, then on the next screen, select Backup again. Go back to the main recovery menu after backup is complete. This step is optional, but to be on the safer side, we advise you do it.

Step 6: Perform data wiping task. To do so, select wipe data/factory reset, then select Yes on next screen to confirm your action. Wait for a few minutes till the data wipe is completed.

Step 7: Then select install zip from SD card and then select choose zip from SD card. Now locate the Liquid-JB-v2.1-Beta1-d2vzw.zip file that you copied earlier in Step 2 and select it by pressing Power button (tap on it if using touch version). Confirm the installation by selecting Yes - Install _____.zip on the next screen. The ROM installation will begin here.

Step 8: Once the installation process ends, repeat step 7. But make sure you choose gapps-jb-20121011-signed.zip instead of ROM zip to install the Google apps package.

Step 9: After the installation is done, go back to the main recovery menu and select reboot system now to reboot the smartphone and boot up into customized Android 4.2.1 Jelly Bean ROM LiquidSmooth. The first boot will take time.

Step 10: If you want to return to the previous ROM, boot into recovery, select backup and restore then restore your previous ROM by selecting it from the list.

[Source: Android Jinn]