This has been discussed before, but...
you can indeed replace the bulbs behind the instrument cluster -- there are 4 or 6 (I've heard both... depends on year, I think) bulbs behind the cluster. autolumination.com sells the LED bulbs, for like 2 bucks per bulb.
EDIT: just a friendly reminder... use the search function before posting. There's a wealth of information on this board already.