Close the LCD screen and turn the device over.

Insert your spudger or other plastic pry tool into the small gap between the device housing and the door.

It's best to do it just above where the word 'close' is printed as that is where the locking mechanism is located within.

Pry open the door with the spudger, using your other hand to tug the door as you work it open.

Caution: this has the potential to damage the plastic piece that locks the door into place.