Junghans MEGA Radio Controlled Watch, ca. 1994

The 4 screws in the case back...
Right next to the snap-on case back have nothing to do with the opening of the watch. First I tought I had to remove these in order to open the snap-on case back. The case back was sitting really tight on this one. Then I realized that these screws obviously hold down the bezel on the front.
More about the opening on the next back pictures.