Our unit does not have the outside TV. I would bet, though, that the outside TV is mounted the same as the inside TV (and is probably the same brand with the same inputs).
I did remove the inside TV and connected up a Chromecast to the 2nd HDMI input:
To get the TV off you have to flip the two tabs forward (one of which is circled in red in the above picture). I had to use a scope to find them and a long handled screwdriver to flip them. It was a major pain..something I don't plan on doing again anytime soon!
Once you get the tabs flipped (which unlatches the bottom of the TV) you pull the bottom out and lift the top off of the bracket.