You can do one of two things: You can buy complete bulb assemblies from FLM (I think they're about $10 apiece and you'll need six of them), or you can buy just the bulbs at any auto store, Wal-Mart, etc. and replace just the bulb units. It's easy.
You'll need up to six replacement bulbs for a complete gauge pod (No. 194s; I just paid $1.69 for a pack of two at Trak Auto). First, gently pry out the variable wiper control (right side) and the gauge light dimmer knob (left); unhook those. Remove the gauge cluster (4 Philips head screws hold on the surround, plus four that hold on the plastic surround on the steering column, plus four more that secure the cluster itself; don't confuse them with the four that hold on the clear plastic gauge cover). Gently pull the gauge cluster out of the dash; while I was able to reach behind the cluster and remove the six bulbs, this is a lot easier if you disconnect the speedometer cable, the vacuum line going to the boost gauge and the wiring harness; then you can lift out the entire gauge cluster.
Once you've removed the bulb assembles (consisting of a white plastic holder plus the bulb itself), you'll need to take a sharp knife (I used an Xacto) to clip a single wire on each side of the bulb holder where the wire from the bulb contacts the metal contact strips on the holder. These wires are very lightly soldered (glued?). I found them easy to snip. Then you'll need to pull out the bulb VERY GENTLY. It is slick and difficult to grasp. I used pliers (repeat: VERY GENTLY) to extract the bulb. This is where it is important to wear safety glasses. Yes, you can break the bulb then you have to dig out the remains. But I just went through 24 bulbs and have broken only one.
Take one of the 194s out of the blister pack; on the bottom, you'll notice two little wires bent back up against the bulb's base. Straighten this out so that they stick straight down. Insert bulb carefully back into the plastic base being sure that these wires make contact with the metal strips. I then tested each of them using jumper wires attached to a 12v battery with alligator clips. Just touch the positive wire to one side of the bulb holder (on the metal contact strips) and the negative to the other and the bulb should light. If it doesn't, you need to pull out the bulb and try again.