Rear head restraints e320

[Robert Hayward]

Hi all new here, and need some advice on how to remove the rear head restraints on a 2004 e320cdi estate. The problem is when the head rest drop button is pressed only the rhs head rest drops the other two remain fixed. I can't drop them manually even when the button on the side of the head rest is pressed, and I can't find any info. on the way to remove them. They appear to be the electrically operated type not pneumatic.

Any help/advice would be much appreciated.