Well, I'll post them for everyone's benefit...
You will need:
Fan switch with tab broken off
Dremel tool with small grinding bits
Soldering iron
Silver or other high-temp solder (thinner is better)
2-3 inch stranded copper wire, at least 14ga or thicker
Female spade connector, preferably weather-insulated
Nail polish (optional)
Tinning your soldering Iron:
Clean your soldering tip with some steel or copper wool. Heat up your soldering iron until just after the tip is hot enough to melt solder. Coat the entire tip with solder and wipe off the excess with a damp sponge or paper towel. Don't wrap the towel/sponge around the tip or you will burn yourself; just wipe gently. *Note* you should also tin your iron before unplugging it. This will make your soldering tips last longer and result in better solder joints.
Prepare the Fan switch:
Clean the head of the fan switch with a wire brush/steel wool, and a cloth with isopropyl, toluene or acetone.
Using your Dremel and a small cone or ball grinding tip, remove the insulating material just around the broken tab until 1-2mm of copper is exposed. Stop removing material if you see metal under the insulation.
In the picture below, I've almost removed too much insulation. No damage, though.
Strip off some insulation from both ends of the wire. One end should be stripped just enough to cover the length of the tab, and the other to crimp to the spade connector. Twist up the wire end and crimp the spade connector to the wire.
Pre-tinning your connections:
Twist the end of the wire up and heat it with the soldering iron for a couple of seconds. Apply some solder to the soldering tip and let it flow into the wire. Add a little more solder until the wires look like they've all been carved from a single piece of metal, but not so much that it just turns into a metal hot dog. Clean the soldering tip with your wet paper towel or sponge.
Do the same with the tab on the switch, using enough heat so that the solder flows and coats the copper. Use as little solder as possible, just enough to coat the metal surface. Properly tinned, the tab should look like it has been heavily painted silver. Clean the soldering tip.
Soldering your connections:
(you may need an extra hand for this)
Lay the soldered wire end along the edge of the tab and heat the wire until the solder flows together with the tab. Add more solder, hold the heat on for another second, then remove. Not enough heat will result in a "cold joint" that will fail prematurely, but too much will destroy the switch. If you have to try again, wait a minute or so for the switch and wire to cool. KEEP THE WIRE AND SWITCH STILL UNTIL THE SOLDER SOLIDIFIES (about 5-10 seconds). A good solder joint will have enough solder to fill in any spaces in the wire, but not so much to make the joint look like a swollen blob of metal. Don't worry if you do use too much solder, though, as it won't cause anything to fail.
Below is a good (but not great) solder joint.
Tin your soldering tip as described above, leaving out the warm-up part, then unplug it.
Weatherproofing (Optional):
Take your nail polish and apply a few coats to the entire top of the fan switch, but not the wrenching surfaces. Let the polish dry for 5 minutes between coats.
You, sir, have just restored a broken fan switch to working order!