I found this really cool pocket watch in the scrapbooking section of Michaels... but the stupid thing came with no directions on how to open it! Not that it should take a rocket scientist, but Google proved no luck either.
After a few minutes of trying to figure out its construction, I noticed that, looking through the glass, the back of the watch has a tiny lip that means that it is not connected to the rest of the piece.
So, to open it is really simple, just grab yourself an exacto knife or a steak knife and pry up the watch from the back. It should pop right off and it pops right back on, too.