Pull down notification bar
Tap on Smartview (you may need to add the button)
Go to Smartview settings
Tap on About Smartview
Tap 10 times on "Smart View" text
Tap Start Second screen
Thanks for sharing!
I followed the steps you mention, but what is suppose to happen after step 6?
What should I do?
After than you follow instructions on your tab to extend the display, and you can choose if you wanna use your tablet as drawing or video playback device.
Thanks to u/Ginger_Bulb from reddit, I stumbled upon a quick workaround that lets you use second screen on any galaxy devices.