All you can do, IMO, is to replace the bulbs with LEDs. There's currently a thread on this forum discussing exactly this; the bulbs are a common, standard size though polarity must be considered. Anything else would likely require permanent modification to the fascia (dash).
Only way I know to replace them is on my back under the dash. IIRC, they're screw-in; the old incandescents should have the type printed on them somewhere.