Ok, hopefully you will never have to do this but we had a flat screen installed and during COVID we wanted to get a new one but didn’t want anyone at home so off to figure out to uninstall a flat screen
The main trick is that behind the TV there is a latch and the key question is how to find it. Sometimes there’s a string that hangs down and you give a yank. Or something to push up.
In our case this safety latch was something that I had to look behind and then give it a pull. Once the safety latch is off then you can lift the flat screen up and remove it.
And believe me a flat screen from 2009 is super super heavy. You really shouldn’t do it alone (but I did!)