Replacing that ugly TV was one of the first things we did to our Landyacht!
Behind the TV is just an empty space with various wires running through. Mike built a cabinet to go in that space, and we relocated the TV to behind the dinette. We got the idea from Trident, from the Landyacht sub-group of the motorhome forum. If you look up his posts, you will find lots of pictures of his installation. I think we posted a few too.
We decided against putting the new TV in the old space because of the screen size limitation and also the awkward viewing angle. There also has to be some way of ensuring the TV can not be used while you are underway, the wiring for that would already be in place from the original TV. No such restriction when the TV is elsewhere.
As you browse around the forum you will also see ways that various LandYacht owners have tackled the bedroom TV as well - we opted to take ours out as we have never used the bedroom TV in any of the RVs we have had. Someone has also done a ceiling mount (for the front TV).
I didn't answer your first question as Mike isn't here right now and I don't have a clue how he took it out, except that it wasn't difficult. If I don't see any replies to your question by the time he gets back, I will get the info from him.
Enjoy your LandYacht! And post pictures!