Using a Phillips #00 precision screwdriver, remove the seven 4mm screws (5 on the bottom of the device and 1 on each of the two sides) holding the back panel to the camera.
On the NX300M model, there is an additional screw under the text AMOLED behind display which should be removed before detaching the back panel of the camera.
Place a plastic opening tool into the gap between the back panel and camera body, from both the top and the bottom of camera. Carefully pry open the camera and separate the back panel.
Using tweezers or a plastic opening tool, release the locks on the ribbon receptors by flicking up the black bars on the holds. Pull the five ribbons away from the motherboard (one hidden from view). This will free the motherboard completely from the device.
To safely remove ribbons, you would need to first unlock the holding mechanism by lifting up the black strip atop the ribbon adapter.
Just replaced the tiny battery on the motherboard. Now I get the correct time and date with my photo’s. Nasty job soldering on the square millimeter, but it worked out fine.