Jelly Bean update
Android 4.1.2 XXEMA2 Jelly Bean firmware is available to download for Galaxy S3 I9300.

Samsung Galaxy S3 with model number I9300 recently received Android 4.1.2 XXEMA2 Jelly Bean firmware update. The update, which brings a few bug fixes and performance tweaks, can be downloaded via Over-The-Air (OTA) and through Samsung Kies.   

The Galaxy S3 users, who have already updated their phones with XXEMA2 Jelly Bean, may follow the guide below to root their devices. The method below uses CF-Auto-Root file, which is released by XDA developer Chainfire, for rooting.  

IBTimes UK reminds its readers that it will not be held responsible for any damage to the device. Users are reminded that the root package is compatible only with Samsung Galaxy S3 I9300; flashing this on any other variant is likely to brick the device.  

Pre-requisites

1) Install USB Drivers for Samsung Galaxy S3 on the computer.

2) Enable USB Debugging Mode. [Press Menu>> Settings>> Applications. From there navigate and tap on Development option and ensure the USB Debugging is turned on.]

3) Create back-up for all the data of the phone.

4) Verify the battery of Galaxy S3 should have charge more than 40 percent.

5) The phone will lose warranty once it is rooted. Moreover, root process will increase binary flash counter.  

6) The method below only roots the device. In order to install custom ROMs, users should install custom recovery separately.

Steps to root Galaxy S3 I9300 on Android 4.1.2 XXEMA2 Jelly Bean  

1) Download CF-Auto-Root package for Galaxy S3 to the computer. Extract the download zip to get a file with .tar extension  

2) Download Odin 3.07 to get Odin3 v3.07.exe along with a few other files

3) Switch off the phone and enter into Download Mode. To do so press and hold Volume Down, Home and Power buttons together. A warning screen will arrive, now press Volume Down button to enter Download Mode

4) Run Odin on the computer

5) Connect the Galaxy S3 to the computer using USB cable while it is in the Download Mode. A message saying Added will arrive under Odin's message box. The COM port with a number in Yellow will also appear, if the phone is connected successfully

6) In Odin click the PDA button and select CF-Auto-Root-mo-moxx-gti9300.tar.md5 file

7) Ensure Auto Reboot and F.Reset Time checkboxes are selected in Odin

8) Double check everything and finally click the Start button in Odin to begin installation

9) Once the installation process is completed, the phone will reboot automatically and soon a Pass message with green background will appear in the left-most box at the top of Odin. Now safely disconnect the phone from the computer

Samsung Galaxy S3 I9300 running on Android 4.1.2 XXEMA2 Jelly Bean firmware is rooted successfully. To ensure the root method is installed and working properly, verify with the root checked app available at Google Play Store.  

[Source: Android Jinn]