How to root your SGH-T999

Links to needed files

Download the files linked below

Odin3_V3.09 downloader link

USB Driver Link

Grab the original T999UVUEMJC stock firmware:

Download link

CF-Auto-Root for Galaxy S3 (T-Mobile) SGH-T999

Power off phone

Boot phone to download mode

Use Odin 3 to install 4.3 stock ROM

Phone will reboot when complete

After 1st boot power off phone

Boot phone back in to download mode

Use Odin to install CF-Auto-Root

Phone will reboot when complete

When Phone is back up and running after 1st boot

Enable SuperSU in Settings/More/Application Manager

Go to Google Play

Apply update for SuperSU

If not showing up, Install from Google Play

Open up SuperSU

Allow app to update/Allow app to disable KNOX

Wait patiently for a few minutes

Reboot device

You now have root