The root directory is the top level of the Android system, and it is what you need access to if you are to run all commands and have access to all files. Having that kind of opportunity is what the administrator of an operating system is all about and in fact being the root user is no different to being the administrator of the system.
Here is what you need to root Samsung Galaxy S6 SM-G920W8 smartphones running on Android 6.0.1 Marshmallow updates by flashing the CF-Auto-Root tool:
- The computer you are using needs to have a version of the Windows operating system running on it to be able to run the flashing tool that flashes the rooting file.
- You need to have the Samsung Galaxy S6 phone that comes with the SM-G920W8 model number to use this guide.
BEFORE WE BEGIN
- Install the Samsung USB Drivers  on the computer so that the phone can get detected by the flashing tool.
- Turn on the USB Debugging Mode  on the Samsung Galaxy S6 SM-G920W8 handset so you can make changes to the Android software.
- Chainfire had the MMB29K.G920W8VLU3CPC5 firmware build number running on the Samsung Galaxy S6 SM-G920W8 smartphone when he developed the rooting file in this guide. He always gives the information regarding the firmware he had running so you can use it as an indicator. However, he is not suggesting you need to run on the same necessarily.
HOW TO ROOT SAMSUNG GALAXY S6 SM-G920W8 RUNNING ANDROID 6.0.1 MARSHMALLOW UPDATES WITH THE CF-AUTO ROOT TOOL
- Download the CF-Auto-Root  tool for the Samsung Galaxy S6 SM-G920W8 smartphone running on the Android 6.0.1 Marshmallow.
- Extract the rooting file to the Downloads folder that is on the PC.
- Run the Odin flashing application from the Downloads folder.
- Boot the Samsung Galaxy S6 SM-G920W8 into Download Mode  and connect it to the computer with the USB cable.
- Do not make any changes to the default Odin settings from the Odin Options tab.
- Check that Odin shows an added message and the ID: COM port lights up with a color.
- Click on the AP button from Odin and browse to the Downloads folder to select your rooting file.
- Click on the Start button from Odin for the rooting to begin.
- Read the information that is rolling down the display of the phone, so you know what is happening.
- Wait until the phone says that it is rebooting in ten seconds and then check for a green pass message from Odin.
In conclusion, that is how to root Samsung Galaxy S6 SM-G920W8 smartphones running on the Android 6.0.1 Marshmallow software updates by flashing the CF-Auto-Root tool by Chainfire. You now have the SuperSU application installed on the Samsung Galaxy S6 handset, and it is all you need to get root access. The app can be opened just like other apps, and you can check out what is inside, but none of its settings need adjusting before you can install and run the root apps. Just find them online and run them to be shown a message from SuperSU.