Scrape all the crud out of it, next time I'll do it when it's still hot instead of waiting..... ummm a while before doing it.
Sprinkle some salt over the whole pan, just regular out of the cheap cylinder salt.
Now start scrubbing the yuck out. We started with paper towels then got ourselves an old dish cloth that will now only be used for this skillet. My super sweet awesome step-dad helped with this project and provided much elbow grease. If you are scrubbing your pan and the salt isn't soaking up the grease any more, dump out the salt and add more in. We had to change our salt out once.
This is what it looked like when we were all done scrubbing. Then we washed it out with soap and water (please don't stone me for this). Just a quick wash around the inside to get all the left over salt and whatnot out okay?
Next put that sucker in your oven. Our oven was hot from baking so we didn't actually turn it on we just let the heat dry it out for about a half hour or so.
This is what it looked like out of the hot oven.
Last take a lightly oiled cloth and swipe it around in the pan to keep it from rusting. We used probably less than a teaspoon of vegetable oil. If you use too much oil it can get rancid in your pans and that would just be nasty.
If you keep your cast iron in good condition they will last you forever and the more you use it the better they get. Happy scrubbing!