I did it with a 2006 unit, and found the best idea was to get the old one out and see what you have for height and width. In my experience, I mounted some extra boards behind the old TV so I could put in a swing arm that retracted and was held in place by the old wooden framework. I put two clasps into the wooden framework that were Teflon and held the new TV locked in while travelling, and were just a twist away from releasing the TV and letting the swing arm out for optimal viewing.
The new widescreen TV's are wider but not as tall as the old units, so you will likely end up with a gap top or bottom. In my case, it allowed the bottom mounted speakers of the new Sony to come into the room.
