Installing ClockworkMod (CWM) recovery and getting your Samsung Galaxy S III (GT-I9305) rooted will help you to get your device to do what an Android device is meant to do; give you the freedom to get your device to work the way you want.
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. Install a custom recovery at your own risk. Installing a custom recovery may void your warranty.
This guide will help you to install ClockworkMod (CWM) recovery on your Samsung Galaxy S III (GT-I9305 — the LTE international version) and get your device rooted using CWM recovery. Please do not try this on any other device. Proceed at your own risk.
Before We Begin
Before getting started with the procedures, get ready with the following packages:
- Download Odin3.zip  on your computer. Unzip Odin3.zip to get a new folder Odin3.
- Download I9305_CWM_Recovery.tar.md5  on your computer. Do not extract this file — you need it as it is.
- Download CWM-SuperSU-v0.96.zip  (or the latest version of SuperSU from its official XDA thread ) to your computer. Do not extract this file. Place this file in the root directory of your phone’s internal storage.
- 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.
- Make sure that USB debugging is enabled in your device (Settings -> Developer Options -> USB debugging).
How To Install ClockworkMod (CWM) Recovery on Samsung Galaxy S III GT-I9305
Follow the steps below to install ClockworkMod recovery on your Samsung Galaxy S III GT-I9305:
- Turn off the 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 (in the folder Odin3 which you had downloaded earlier) 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 I9305_CWM_Recovery.tar.md5 file that you had downloaded earlier.
- 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.
- Wait till the device automatically reboots.
- Unplug the USB cable.
How To Root Samsung Galaxy S III GT-I9305 using CWM Recovery
To root your Samsung Galaxy S III GT-I9305 using CWM recovery, follow the steps below:
- Reboot your device once before following the steps below.
- Hold down the Power button to turn off the device (if its not already off).
- Keep pressing “Volume Up + Home + Power” buttons combo to boot into CWM recovery which you had just installed.
- Take a backup of your device by choosing ‘backup and restore‘, and then select ‘backup‘.
- After the backup is complete, ‘go back‘ to the main menu of CWM recovery.
- Select ‘install zip from sdcard’.
- Select ‘choose zip from sdcard’.
- Now select the file CWM-SuperSU-v0.96.zip (or the latest version of SuperSU) that you had downloaded earlier.
- Choose Yes, and CWM recovery will now start installing the file.
- After successful installation, you can reboot your device by choosing ‘go back’ and then ‘reboot system now’.
- Done! Your phone is now rooted (if everything went fine)!
- Open up your Apps list and you will notice a new app ‘SuperSU’. You can access it anytime to manage root permissions for different apps.
Enjoy an extensive CWM recovery along with the power of root on your Samsung Galaxy S III (GT-I9305). Now you can do things such as manage app permissions, make advanced backups, block ads  or deny apps Internet access .
[via XDA ]