I have dismantled the acute matte screens to clean them when there is gunk condensed between the screens (looks like tiny droplettes that interfere with focus), or when capillary action draws in liquid from a wet clean, and leaves residues.
There are only 3 parts to the screen, the glass plate (top), the plastic acute matte plate (bottom), and the frame. You gently pry the plastic plate out of the frame from below, once you get 2 sides out, it should come out easily as the 3rd side is pryed out. The glass follows easily. The separate plates can be washed with soap and water, or other cleaners (ie US cleaner if you have one). Reassembly is just he opposite, no tool required.
It is important to note the orientation of the plastic plate (top and bottom surface).
The plastic acute matte plate is ... plastic! So it is easily scratched. If you don't have steady hands, or you are not comfortable using a hard (steel) tool against expensive plastic, DON'T DO IT.
Also mentioned
http://photo.net/medium-format-photography-forum/00EfEB