I had the same issue this last week with the clock bulb blown, difficult in the day to see and impossible at night. I purchased a $2.50 T5 white LED globe (part number ZD0384) from Jaycar. Used two plastic cards to pop the clock out as suggested elsewhere, replaced the bulb and all working fine now. All done within 5 minutes. The display is a lot brighter than when the original bulb was there - a big difference.

Now I have to work out how to get to the A/C switch bulb and replace that one.

Mike