These are the guidelines to install CWM Recovery on Samsung Galaxy S3 SC-03E DoCoMo smartphones running any firmware.

REQUIREMENTS

• You can have your Samsung Galaxy S3 SC-03E rooted or unrooted when you flash a custom recovery on the device. In other words, it doesn’t matter if you choose to root before or after flashing your custom recovery.
• You will lose the data on your S3 smartphone if you have no previously unlocked the bootloader on the device before starting this guide. Therefore, you need to back up any data on the device so you can restore it later.

BEFORE WE BEGIN

• Unlock the Developer Options menu so it is no longer hidden from the Settings by tapping on the Menu > Settings > About Device > Build Number at least seven times and it will eventually say you are using the smartphone as a developer.
• Turn on your USB Debugging Mode from the Developer Options menu by tapping on the Menu > Settings > Developer Options > USB Debugging Mode.
• You are voiding the Samsung warranty when you choose to root and ultimately customize the DoCoMo variant of the Samsung Galaxy S3 device. You can flash the stock ROM for your SC-03E model number at any stage and the warranty will start working again. That isn’t typical of a flagship Samsung smartphone; the newer models come with Knox security and once you trip Knox the warranty is gone.
• Download the Samsung USB Drivers for mobile phones directly to your computer so the Samsung Galaxy S3 smartphone can talk to the computer and the programs running on that computer.

HOW TO INSTALL CLOCKWORKMOD RECOVERY ON SAMSUNG GALAXY S3 SC-03E DOCOMO

1. Download the CWM Recovery for the Samsung Galaxy S3 DoCoMo from this link.
2. Download the latest Odin flash tool from this link.
3. Download both the above files to the desktop of your computer and right-click over the files to select the “extract here” option.
4. Long-press the Power button on the S3 and wait until the device is completely off.
5. Boot the Samsung Galaxy S3 in download mode.
6. Connect the S3 to the computer using the USB cable.
7. Click the PDA/AP button and upload the CWM Recovery tar file from the desktop.
8. Click the Start button without changing any of the default settings from the Odin user-interface.
9. Do not touch anything until you can see the pass message from the Odin user-interface.
10. Wait for the DoCoMo variant of the Samsung Galaxy S3 to reboot automatically and do that manually if it never happens.

Now you are ready to boot your Samsung Galaxy S3 smartphone up in the custom recovery mode. We encourage you to do that during the guide and not later because you need to update the root binaries. Reboot the Galaxy S3 holding down the Power + Home + Volume Up buttons together and wait until you can see your custom recovery loading. You will be asked if you want to update the root binaries once you enter the custom recovery mode. Agree to do that and you’re finished.

You can choose the ‘Reboot System’ option from the recovery men if yo would like to go back to normal mode and use your device. otherwise you might like to try taking a NANDroid Backup or search for some custom ROMs to try like the latest from CyanogenMod.

Those wanting to complete their customizing of the Sammy S3 experience can try rooting the DoCoMo Samsung Galaxy S3 smartphone using the Cf-Auto-Root tool by Chainfire.