Before commencing:
See, if the S3 is an international variant. The model number should be GT –I9300 Ensure battery is 80% Have a backup of the data with custom recovery instrument such as ClockWorkMod Enable USB debugging
Updating Galaxy S3 to Official Android 4.3 Jelly Bean (XXUEML8) 10.Choose the Odin start button and proceed with installation. After installation, phone will restart