If you follow these instructions, you can do it yourself for about 20 minutes of your time and ~$22.90 in parts. Also, once you replace the bulbs with LEDs, you shouldn't ever need to replace them again. This picture is of one of the new LEDs connected to a 12V power source.
I got the idea for this instructable from a 2007 forum posting at http://forum.chryslerminivan.net/showthread.php?t=6856 which provided the basic instructions on how to disassemble the dashboard.
Step 1: Parts and tools
The instrument cluster of the 2001 Voyager needs 8 bulbs. The replacement bulbs are PC74 (a #74 bulb with a twist-lock holder for mounting). I ordered QTY - 10 of #T1.5-B Blue LEDs (8 plus a couple of spares) from http://superbrightleds.com. They have LEDs for just about any vehicle, and not just dash bulb replacements, but others as well.
A small pair of needle nose pliers - to twist out the old bulbs and install the new LEDs
#1 Phillips screwdriver(s) (short and long reach) or a combo type with a drive extension (preferably with a magnetic tip).
Small flat blade screwdriver - for prying a cover later.