Next, remove the inner plastic frame, also held on by lots of integral plastic clips, just like the outer frame.Then remove and safely store the two or three flexible sheets, noting the orientation and order of the sheets. (Good idea to keep them together).

Then remove the flexible white reflector sheet to fully expose the 2 LED strips with glued on lenses for each LED, as in the image.

Remove 3 screws from the green circuit board (red arrow), and slide it off the glued-on LED strips so that they are electrically isolated and ready for testing.