Tailgate Microswitch Problems: Dirt & Fixes

Hi.

When I want to open my tailgate, I press on a rubber surface underneath which there's a touch-sensitive area with a microswitch.

Now it seems like there's dirt between the rubber and the touch surface, because there are little bumps that are moving around.

Do I need to remove the interior trim of the tailgate now, or is the component installed from the outside?

m;

The interior trim of the tailgate needs to be removed.

Document with images follows.

m;

Okay, I'm ready. Please provide the German text you want me to translate.