After the batteries are removed the case can be disassembled.
First, apply pressure with your thumb on the top of the battery cover.
Next, pull down on the cover until it begins to slide.
Finally, once the cover is completely off, pry up the old batteries with your finger or a strong, skinny tool (i.e. spudger).
Unscrew the six 8.0 millimeter long, #0 screws on the backside of the case using the Phillips #0 screwdriver.
Detach back part of the case by gently lifting up.