I know there are several how to root posts here but none are written in a way for the noob to understand. I decided to put together a detailed step by step guide for the beginner. This method isn't any different and doesn't bring anything new but it is written in a way that is easy to follow and understand. I would like to thank Team Epic for all their contributions.
Skunk Ape1 is not responsible for your phone. This is for the SPRINT GS3 ONLY!! By Using this guide you are assuming all the risks.
Sprint GS3 Root Kit
-----Preparing your computer-----
Double click on the Sprint GS3 Root Kit and drag the Sprint GS3 Root Kit Folder to your Desktop.
Your Samsung Drivers MUST be installed correctly on your computer prior to continuing.
-----Install your Sprint Samsung Drivers-----
Open "Sprint GS3 Root Kit" Folder
Double click on "Sprint-Samsung-USB-Driver.exe"
Wait until the software installs completely before plugging your device into the computer. When you have completed driver installation.
Plug your device into the computer with your usb cord. The computer should now tell you it is installing drivers, click on the details and wait until there is a green check by all the drivers. Unplugging your device before it's complete will cause you problems...
-----Preparing your Phone-----
Open "Files to put on your phone" Folder and copy "TeamEpic-Root-from-Recovery-v5.zip" to either you internal or external sdcard. Or you can download it directly to phone from this url: http://www.mediafire.com/?h203ct9rbn0cmnp and move the downloaded file to your internal or external sdcard.
Download mode is achieved by turning off the phone. Then pressing and holding "volume down, power button and the (physical) home button simultaneously. You will continue to hold all 3 buttons until you see a warning. Then press the volume up button and you will be in download mode.
Recovery mode is a bit trickier. If you're a second too early or too late, your phone will skip going into recovery and boot normally. If this happens you will have to repeat the Odin process in it's entirety. So unless you are familiar with this, I would give it a few practice runs before starting Odin
Recovery mode is achieved pressing and holding "volume UP, power button and the (physical) home button simultaneously. Watching the screen closely, release all 3 buttons as soon as you see the word Samsung. If timed correctly it will boot into recovery in about 10-20 seconds (after releasing). Remember if you are too early or late the phone will boot normally and skip recovery.
DO NOT LET THE PHONE BOOT AFTER FLASHING RECOVERY IN ODIN.. IF YOUR PHONE BOOTS BEFORE FLASHING TEAM EPIC ROOT FROM RECOVERY IN CWM, CUSTOM RECOVERY WILL NOT STICK AND YOU WILL HAVE TO START OVER..
For those who prefer TWRP Recovery (Which isn't in the kit) I am adding it here. Just replace the recovery.tar file provided in the kit with this one and you will have the most recent TWRP Recovery. Just flash it in Odin the same way you would the cwm provided in the kit.
Download TWRP 188.8.131.52 here.
1. Open the "Odin307" folder and right click on "Odin3 v3.07.exe" and choose run as administrator. Odin will open.
2. Remove battery cover from phone for future access
3. Place your phone into download mode. See above Download note.
4. Plug your usb cord to your phone and computer and wait until you see any number and com in the com block
5. Click on the PDA button and browse to "recovery.tar.md5" in your Root GS3 Folder.
6. Verify that both Auto Reboot and F. Rest Time are UNCHECKED.
7. If everything is like the picture click on the start button. It should move very quickly as recovery is a small file. It is normally completed within 10-20 seconds (depending on the speed of your computer and usb port).
Sometimes Odin will not show "PASS!" in the top left corner until after the phone is unplugged. So observe the message window as well. If it shows "All Threads completed (Succeed 1 / Failed 0) you should be fine.
8. Remove Battery and disconnect phone from computer.
-----Flashing Root in Recovery-----
1. Install battery
2. Place your phone into Recovery Mode.
-----INFO-----The Recovery that you installed is a touch screen recovery. You will not need use the buttons to navigate through the recovery menus.
3. Once in recovery tap on "install zip from sdcard".
4. Now you will tap either "choose zip from sdcard" or "choose zip from external sdcard"
5. Scroll by swyping up and down on screen. Tap on "TeamEpic-Root-from-Recovery-v5.zip.
6. Tap on "- Yes - Install TeamEpic-Root-from-Recovery -v5.
Once complete, tap the "go back" button once and then tap "reboot system now".
You Are now fully rooted with custom recovery installed.