This is a simple illustrated guide to show how to root your Galaxy S III and have CWM ( ClockworkMod Recovery ) installed. Rooting your phone will void warranty. It is a very safe process and the chance you will brick your phone is close to zero.
The process essentially is 2 steps :
1. Use Odin in PC to flash the Chainfire kernel to have ClockworkMod ( CWM ) Recovery installed. This will create a flash counter as is not a official kernel. You cannot remove this counter at present even using the USB Jig
2. After CWM is installed, boot phone to RECOVERY mode and flash the SuperSU zip to have root enabled
Prerequisites : Have these installed in PC first
1. Samsung USB Phone drivers – necessary so that PC can detect the G Note. Download this from my box:
2. ODIN 1.8.5 : this is necessary to use in PC to flash any rom ( in tar format ) . Download this from my box :
4. Connect phone to PC using the USB cable
5. Launch ODIN in PC. You will see the phone is successfully detected by seeing the Yellow small box with Com number shown
6. Select PDA and browse to where you have keep the CWM tar file. Select the CWM tar file. Make sure Repartition is not selected and that Auto Reboot and Reset time is ticked. Press START
The flash process will take less than a minute. On completion you will see RESET shown in the Odin window. Allow the phone to reboot itself. This will take about less than 2 mins
7. After phone is successfully booted up, boot to RECOVERY Mode by simultaneously pressing Vol UP + Home + Power buttons . You will see the CWM Recovery mode 22.214.171.124
8. Now proceed to ROOT the phone. In Recovery mode, Select ” install zip from sdcard” than ” choose zip from sdcard”.
9. Browse to the file CWM-SuperSU-v0.89.zip and select it. Select YES to install this zip file. The flash will just take few seconds. Select Go Back and Reboot System. Phone will bootup within a minute and your phone is now rooted.
10. Check for the app SuperSU in the apps drawer. test the root status by downloading apps that need root such as Titanium Backup, AdFree, Terminal etc
Forum XDA reference : http://forum.xda-developers.com/showthread.php?t=1684535