Trim removal for access to sockets (1 Viewer)

[Welsh girl]

I want to remove this trim to get to the top socket to find and replace the wiring to the outside satellite/aerial socket.
Can anyone tell me how it comes off please.
At the moment the wiring is going to the splitter attached to the freeview aerial on the roof but we want to attach the wiring to an outside dish via the socket outside the van.
The wire you see is going through the windows which is not ideal as we cannot close the blinds at night.

 

[pappajohn]

I would expect it to be screwed into the edge from behind the panel it butts against behind the tv.
That in turn will have hidden screws possibly under plastic button caps.
I needed to remove a similar panel in my caravan...took a lot longer to figure out the fixings than actually cut out for, and fit, a second socket.
The converters do a terrific job of hiding screws.