Help me out here...is this the R129 model or the R107?
I can help you if this is the R129 model...mine went out a couple of years ago and i replaced them myself (also did the "banging on the dash" thing for awhile
).
The plastic panel comes off pretty easily. In fact you can lift from the left and right sides with your fingers and gently pry the rest of it off with a small flat-tipped screwdriver. It's only held on with the clips attached to the actual panel.
Underneath is a clear plastic bezel located in front of the bulb housings. Just lift right off.
Get some tweezers to pull the bulbs from the housings...they are tiny.
They also come integrated in their own little receptacles (blue or black, depending on replacement age). These are 1.2W bulbs.
Some here have mentioned other sources for these bulbs, but I have had a hard time finding them anywhere but the dealer parts counter...they run about $2-6 there.