Warning: You should always remember that rooting voids the warranty of your device. If you don't know exactly what this is all about then leave your device untouched. Proceed at your own risks!
Now, head over at XDA-Developer for the necessary files and the step by step rooting process, prepared by [open1your1eyes0] Here.
There's also a pre-rooted stock VRBMB1 for those who chooses de-odexed or odexed stock, created by [Scrosler] (CleanROM developer) Here.
Below is just a visual aid for beginners that might get confused from the advance users guide.
Flashing the Bootchain with OdinThe first bootchain is VRALEC, you need this so that you can install the Custom recovery of your choice like CWM (ClockworkMod Touch Recovery 188.8.131.52) or TWRP(TWRP Recovery 184.108.40.206).
Assuming the you already installed the USB driver. Now run Odin then click on PDA button then browse to the downloaded VRALEC.bootchain.tar.
Boot the Galaxy S3 into Odin Download Mode
Turn the Power Off. Then gently Press the "Volume Down" and "Home" Button then smoothly press the "Power" button button. Release the keys when a warning screen appears, then press volume up to get into download mode screen. Once it displays the Android robot, connect the phone to PC.
Hit Odin's "START" button to flash the VRALEC bootchain. Just wait until it finishes.
Flashing the Custom Recoveries CWM or TWRP with OdinYou need to choose the custom recovery of your choice, either CWM or TWRP. You will need this so that you can the install the SuperSU apps via SD card update zip option.
Download the TWRP or CWM onto your computer.. Now load the CWM or TWRP tar files onto Odin's PDA button. This time Uncheck the "Auto Reboot" checkbox option.
Flashing with CWM - load the CWM6012TouchVZW.tar.md5
Flashing with TWRP - load the TWRP2310VZW.tar.md5
Now boot the phone into download mode again, then hit "Start" to flash the custom recovery. Remove the phone from PC once finishes.
Install ROOT or Unlock BootloaderOnce you already installed custom recovery is in place, put the root.zip on your SD card . . . boot into recovery mode and select the "install zip from sd" or whatever the wording is that is there . . . use the "select zip" menu and point the recovery program to the correct zip file you are installing
Restore the Original Jelly bean VRBMB1 4.1.2 Bootchain
This step is optional but recommended to return your original partitions after you see everything is working properly
- Boot phone into ODIN mode
- Flash the VRBMB1 Bootchain using ODIN v3.07
- After a final reboot, you are all set to use your device as needed