Summarize the following:
This will help prevent data loss in the event complications arise during the rooting process. ” ” This will allow you to install apps from outside of Google Play Store, including Towelroot.  This will download the .apk file for the Towelroot application. The application will start downloading, and appear in the Notification Tray when complete.  ” Towelroot will complete the installation process on your Galaxy S3. ” Towelroot will automatically root your device, and reboot when complete. Your device will now be rooted, and SuperSU will display in the app tray.

Summary:
Back up and save all personal data on your Galaxy S3 using Samsung Kies, Google, your computer, or a third-party cloud storage service. Tap on Menu and select “Settings. Tap on “Security,” then place a checkmark next to “Unknown sources. Navigate to the Towelroot website on your device at https://towelroot.com/. Tap on the large red lambda symbol displayed on-screen. Tap on “OK” to confirm you want Towelroot downloaded to your device. Swipe down from the top of your screen to open the Notification Tray. Tap on the Towelroot .apk file, then tap on “Install. Tap on “Install anyway” at the warning to proceed with installation. Tap on “Open” to launch Towelroot, then tap on “make it ra1n. Wait for your Galaxy S3 to fully reboot.