1948 'Arnold'

Hi Sfjones. Looking at the case back, as in the above photo, you will notice a little protrusion on one end between the lugs of the watch. Put a knife or a case back opener tool between that protrusion and the watch band and twist it so that you are pushing up on the case back and it should pop right off. It will snap back on just using a little pressure with your fingers. 

Oh. Lay the knife in a position across the lugs. Not in a position like you're trying to force the band off the watch.