I am trying to replace the clasp on the standard AP strap with a buckle. Question now is, what is the secret to take the clasp off without damaging it. I took the screw off but that really makes no difference. Here is a pic off it....
That pin should be pushed from one side or the other. I bet it's fused or dimpled a bit from the set screw. I would use the loupe and confirm. My Chopard worked the same way.