from the user manual press the button closest to the seconds display on watch . bottom right button in normal time display to switch between am / pm time or 24 hundred military time.
http://mygshock.com/casio-manual/548/
enlarge the internet browser display to read which button to press to change the time or date.
press button B top left button to go into change mode
press button C bottom left button to move to seconds or minutes or hours .
press button A bottom right button to advance the time
press button b top left button to go back to normal time display
I think the one I have may help - its for a 1950 but it says WR50M on the strap.
I have no idea how to attach it so email me at [email protected] and i'll send it to you.
probably needs a new battery,cr2016 should be, see videos on youtube on how to replace.What I found was connecting the AC pin to the top of the battery,which is the posive resets the watch after new battery in
