If you own Galaxy S advance and want to try Android 4.2 Jelly bean on it, then you can install the custom ROM on it using the guide which will be discussed later in this post. Before we proceed with guide, make sure:
  1. You have installed your Galaxy S Advance USB drivers on your PC.
  2. You need to enable USB debugging mode which is deactivated by default.
  3. You smartphone should have 70-80% charge remaining.
  4. Your Galaxy S Advance should be factory unlocked.
  5. Last but not least, backup your important data like Call logs, SMS and other data in stored in phone memory so in case if anything goes wrong, your data is not hurt

Android 4.2 Jelly Bean Custom ROM for Galaxy Advance I9070

Step 1) Download Android 4.2 custom ROM for Galaxy S Advance.
Step 2) Connect your Galaxy Advance I9070 to your PC via USB cable.
Step 3) Copy the download 4.2 custom ROM files on to your SD card.
Step 4) Now Turn OFF your smartphone and disconnect it from your PC.
Step 5) Now you will need to turn your Galaxy S Advance again in recovery mode by pressing and holding the Volume UP + Home Buttons together for few seconds with a Power button.
Step 6) Now wipe the data first by selecting wipe/data factory reset.
Step 7) Now select Flash Zip from SD Card and select the custom ROM you downloaded in step 1.
Step 8) Once the the installation completes, go to “+++++Go Back” and reboot the phone by selecting reboot option from recovery menu.
Voila! Now you have successfully updated your Galaxy S Advance to Android 4.2 custom ROM..