Amel 55 Fwd shower valve leaking

Billy Newport

I noticed yesterday that the fwd shower is dripping when turned off. It looks like a Paffoni brand shower mixer, the other taps in the bathrooms are similar brand.

Is there a rebuild kit for these? New washer or something? How do I remove the panel to get behind the shower fittings to service them. I can see screws on the top and bottom of the aft shower tap "box" but the fwd one has nothing obvious.

Amel 55#56