This guide will help you to root the AT&T version of Samsung Galaxy S3 to enjoy the real taste of your device, to full extent. If you are looking to root your Sprint, T-Mobile, Verizon, or International versions of your Samsung Galaxy S3, please refer to their respective guides, rather than taking a risk by following this guide.

Disclaimer: This guide is intended as a helpful “how to”. dotTech and its writers are not responsible for any gain or loss (including but not limited to bricked devices) incurred as a result of following this guide. Root your device at your own risk. Rooting may void your warranty. Instal a custom recovery at your own risk. Installing a custom recovery may void your warranty.

Requirements

This guide is applicable to the AT&T Samsung Galaxy S3 on Ice Cream Sandwich, to help you root and install ClockworkMod recovery on your device. Proceed at your own risk.

Before We Begin

Get yourself equipped with the following before starting with the procedure:

• Download stock_root67.7z to your computer. Extract this file to obtain stock_root67.tar.
• Download Odin3-v3.04.zip to your computer. Extract this file to obtain Odin3 v3.04.exe.
• Samsung USB drivers for Windows, if you are running Windows, or the drivers for Mac or Linux if you are running those. Install the drivers if you haven’t installed them already.
• Download either of these packages:
  • Official CWM recovery (recovery-clockwork-6.0.1.2-d2att.img) for AT&T. Do not extract this file.
  • Universal recovery by Team Epic that reportedly works on all Samsung Galaxy S3 LTE variants. Extract this file to obtain recovery.img (if you are having problems trying to extract the file, remove the .md5 extension and try again).

  Copy either of these files (recovery-clockwork-6.0.1.2-d2att.img or recovery.img) to the root directory of your phone’s internal storage (/sdcard).

• To install ClockworkMod recovery on your device as per the instructions of this guide, you need to have either:
  • ADB (Android Debug Bridge) installed on your computer.
  • Terminal Emulator installed on your device (required only after rooting your device, it is not required if you want to just root your device).
• Make sure that USB debugging (under Settings -> Developer options) is enabled in your phone.

How To Root AT&T Samsung Galaxy S3

First, let us start with rooting your device. Follow the steps below to root your AT&T Samsung Galaxy S3:

• Turn off your device.
• Boot into Download Mode by keeping the ‘Volume Down’ and ‘Home’ buttons pressed while pressing the ‘Power’ button (Volume Down + Home + Power), until you see a WARNING! screen.
• At the WARNING! screen, read it and press ‘Volume  Up’ button to enter Download mode.
• Double-click Odin3_v3.04.exe to launch Odin.
• Plug-in your device to the computer using USB cable.
• After you plug-in the device, the first box at the top of Odin, i.e, ID:COM will turn blue and the message ‘Added’ should appear in the message box in Odin.
• Check that ‘Auto Reboot’ and ‘F.Reset Time’ options are enabled and that no other options are selected.
• On the Odin window, click on PDA button and select the stock_root67.tar file that you obtained earlier after extracting stock_root67.7z.
• After verifying all the settings again, click on ‘Start’ to start the flashing.
• Wait until Odin does its thing. The box at the top of Odin shows ‘RESET’ after the flashing procedure is complete (it will show ‘PASS’ after everything has been done successfully).
• Wait till the device automatically reboots.
• Unplug the USB cable.
• Congrats! Your phone is now rooted!

The rooting procedure is now done with, and if you just wanted a rooted phone with the official ROM, you can stop here. If you would like to get your hands on the wide range of features ClockworkMod recovery has to offer, continue reading.

You can install ClockworkMod recovery on your AT&T Samsung Galaxy S3 either using ADB or using Terminal Emulator for Android.

How To Install CWM Recovery Using ADB

• Connect your phone to your computer.
• Open a command prompt (First, press Win + R to launch the Run dialog, then enter “cmd” in the dialog box).
• In the command prompt, enter the following commands one after another:
  • adb shell
  • su
  • dd if=/sdcard/recovery.img of=/dev/block/mmcblk0p18
    (Replace recovery.img with recovery-clockwork-6.0.1.2-d2att.img if you had chosen to install the official ClockworkMod recovery)
  • adb reboot
• Done! If everything went right, you should have now replaced your boring Android recovery with the stunningly exciting ClockworkMod recovery.

How To Install CWM Recovery Using Terminal Emulator

• First of all, make sure or verify that you have Terminal Emulator installed on your device.
• Open Terminal Emulator and run the following commands one after another:
  • su
  • dd if=/sdcard/recovery.img of=/dev/block/mmcblk0p18
    (Replace recovery.img with recovery-clockwork-6.0.1.2-d2att.img if you had chosen to install the official ClockworkMod recovery)
  • reboot recovery
• Done! If everything went right, you should have now replaced your boring Android recovery with the stunningly exciting ClockworkMod recovery.

Conclusion

Enjoy a rooted AT&T Samsung Galaxy S3 along with the extensive ClockworkMod recovery (if you chose to install it). Now you can do things such as block ads or deny apps Internet access, flash custom ROM’s such as Cyanogenmod.

[via XDA]