Some time ago I purchased an used Casio Diver amw-320d. I realized that the analog time keept changing randomly. Finally, I discovered that if you shake the watch, the hour hand turns randomly. It's loose, so that explains it.

I have even recorded a video of it:

Seems that if you don't move the watch at all, it works OK.

Is there a way I can fix this for myself?

And any idea of how hard and expensive would it be to have it repaired by someone else?

Thanks in advance,