Hey! That's my car! I recognize my Nav & unique color scheme. Who better to answer your ???s then.
Pertaining to the armrest…there are 2 pins in each. I used a wire to "poke" them out. You could use a larger paper clip, or I suppose, a punch would work. They are quite easy to remove. Just look on the underside of the armrest, the solution will be easy.
BTW, what color are you trying to paint? I thought about placing a cushion (foam) on there and using leather, bind it to the armrest…but then I remembered…it's not a Mercedes!