Well, there are some posts that describe how to buy little plastic gears and install them.
I recommend you learn how to remove the instrument cluster. its simple.
Remove the under dash panel, hopefully without cracking it
then there is a oil line that requires a 10mm wrench (a short wrench is better than a long one) its on the back side of the oil gauge. Loosen the nut holding it on, blind of course, using your feel (its easy, trust me!) then loosen the nut all the way till it comes out. Place an open plastic bag over the open line and tape it on to catch any small oil drops that might come off it.
Do not start the engine while it's off!
Now push the instrument cluster from the back until it comes out. Don't try to pry it from the front, that's a recipe for broken plastic!
Unscrew the speedometer drive cable.
Now it should come out far enough to see and remove all the wires, noting where they go, the individual wires to the lamps I mean, then the big electrical connector. The wirtes have to goi back to the same spot if you want the right indicators to light when its all back together.
Now carry the while thing over to Palo Alto Speedometer. Let them remove the speedometer and oil it and check for broken gears etc.
If you want to splurge, ask them to replace the trip odometer wheels with a new set and then they will be nice and bright and easy to see!