Flash is not working. How can I replace/test the flashlight

Hi all,

after my son dropped the nikon 1 j1 camera the flash didn't work anymore. The camera ist still working fine, also the photometer which decided if the flash ist needed or not.

So there could be a problem in the wiring or the flashlight itself is broken. To test the flashlight i try to dissamble the flash and removed the clued plastic cover. Behind there is one screw. Unfortunately the screw won't move.

Now my question. Is there anyone who have already experience with an nikon 1J1 flash disassembly and how can i reach the flashlight?