Have the
same answer as your other question of TV replacement.
In the links there are questions asked and answered.
For instance here is
one for a 2007 DS.
Newmar's mounting of TV's do not change that much between models.
You may have buttons to remove on dress face surround, or buttons under the TV box or screws in each cabinet both sides of TV to remove and the surround will slide out from around the TV.
You need to read the different TV links to get a start and look at the different methods of mountings people have used.