I just fixed mine. There are four bulbs, with blue covers that twist into the PCB. They are like the cluster bulbs but smaller.
Can't find new bulbs anywhere. I reused the bulb housing and replaced the bulb with RadioShack micro-lamps. Unwrap the bulbs leads to remove the old bulb from the bulb housing. Try to reuse the blue bulb cover.
Access is by popping out 1 inch by 6 inch cover just below the bezel. Then remove two screws. Then pop bezel off. Disconnect wiring connectors. Turn knobs all the way counter clockwise (Off) then remove. Remove 4 screws from back of HVAC unit.