On a 93 the back light that illuminates the fan speed, temp controls, and vent dial flickers on and off. If i smack the side of the dash it comes on but eventually goes back out. Now i pulled the dial knobs and took out the screws and took off the black face plate to reveal the bulbs. I cannot see how to remove the bulbs from here. There is a white face plate that hold the bulbs but i cannot maneuver this out to take out the bulbs. What am I doing wrong?