DG-200 Water Valve

One off the dump valves on my DG-200 is not completely closing. It seems
that the spring mechanism that pushes down on the plug to seal it when you
close the dump valve doesn't have enough "oomph" to completely close the
valve. I suspect that a good cleaning might be all that is required, but
if not I might need to replace the spring or make some other repair to the
mechanism.

The valve assembly is housed inside a plastic box in the wing root. The
box is secured by a number of screws. In order to remove the box, you
need (as one of my club-mates observed "Little Elphin Hands."). I don't
have elphin hands, but I do have a large variety of tools with which to
attack this problem.

However, having never removed this valve assembly before, I am looking for
tips or pointers, specifically:
1) Any easy way to remove the screws?
2) Once I get the screws off, what's inside the plastic box? Am I going
to little springs and ball-bearings flying out all over the place once I
loosen the last screw?
3) Anybody have a picture/drawing/procedure related to the valve
assembly?
4) Anything else I should know?

Any and all tips are greatly appreciated.

--
Stefan Murry