The back of the case seems to be pretty well sealed, so I start opening it on the front.

I insert a paper cutter in the narrow gap between the white light cover and the casing and gently pry upwards. Any other very thin opening tool should work as well.

Turns out the light cover is only lightly adhered and clicks off easily enough. I proceed along all four edges, gently prying upward, and soon the cover is removed.