On the properties which have the Smart TVs (Netflix/YouTube/Pandora) built in, you'll usually find a small box behind the TV. If you disconnect the RJ-11 (telephone cable) between the cable box and TV, you'll find the TV becomes a plain-old TV and works normally.
If you stumble across an LG box behind the TV, I've had good luck with just plugging my device into the LG box and hitting Source / Input on the remote, no hackery needed.