Yes, yes in order to remove the top screw I had to release that level what you use to stop the alarm and the stop button too. Actually the top screw goes trough the outer case and the inside frame. The inside frame was also bent, so it was actually enough to put the top screw in and tighten it to stop the clock. I straightened up the bent and now the top screw is not an issue anymore. Hopefully I can sort this out, thanks for both of your comments.