When I tried to remove the TV from our 5er when brand new, I could not budge the d*mn thing. I tried and just couldn't find a way. Now thieves broke into it while it was at the dealer for minor repairs and took the TV, receiver, bedding and memory foam topper off the bed. They broke into 29 trailers that night as I found out later, so they had to be fast, I'm thinking. The TV was located at the rear of the 5er and there are 2 slides at the rear. When the slides are closed there is, maybe a foot and a half of open space. To this day I am still wondering how they got the TV off of the cabinet and out in that little space. They were neat tho'. They just unplugged everything but they did try to pry the door open and the dead bolt held so they forced two windows before they could get in. They ripped off a cabinet door above where the TV sat and found the remotes. Insurance replaced the door and the windows, the TV & receiver and the bedding. That was in June of that year and didn't get the 5er back until the middle of August.
Now the present TV is easier to get out as I installed a swivel mount and 4 screws are loosened to lift it off the mount. When the 5er is in storage, the TV & receiver come out and are put in the basement of the S&B. I did ask the mechanic at the dealer and he said to pull on the wire that was at the bottom of the mount, Never did see that wire. Maybe do as youroo suggested but stick around the trailer and and ask the rotters how they do it.....
. I just thought of something...maybe the dealers should hire some of those thieves and they could be there when a PDI is done to show how they remove these things. Good luck.