My GE Profile refrigerator has a temperature controlled bin in the bottom of the refrigerator side. Recently, its temperature has gone too low (about 25, is set to 35), and the fan down there is running all the time. I assume that the "thaw heater" (AP3772890) or the control electronics has failed. How do I get the upper cover ( AP3186947) off to check it? I removed the screw at the back middle of the cover, and I released the two snaps at the right side of the cover and the one snap at the front left. However, the cover is still firmly attached somehow to the center wall of the refrigerator.