It should be straight forward.
Plug in HDMI lead and the GeForce control panel should detect a second display.
Using the control panel go to the multiple display options to choose clone, singular or extended.
That's all I need to do. That said the input lag is a little crappy once your used to the 120HZ screen.
Yeah, I wanted to keep laptop screen active whilst gaming on the tv and couldn't find a way to do that?
(Only plugging into the tv to play pCars @ 4k).