How do you get rust off a cast iron frying pan and then re-season it?

Good question! I have a number of pans I want to reseason myself and did a lot of research into it, though it's a project that still needs to be done. Mine aren't rusted but I believe this would work on it as well: the best suggestion I found was to use EasyOff first--the horrible stinky kind, not the easy EasyOff--to strip it to bare metal, then season with flaxseed oil. From all I read, this will give it a finish that's almost unstickable. Why have I not done it? Flaxseed oil isn't something one can pick up at your local grocers or Walmart. Whole Foods may have it, but the closest to me is an hour away. You can order from Amazon; I just haven't done it yet. For more details, check out this website: http://sherylcanter.com/wordpress/2010/01/a-science-based-technique-for-seasoning-cast-iron/ If you opt to do it, let us know how it works!

Try rubbing lemon and apply salt.

The only way I know how, is with oil, any kind if cooking oil , just keep rubbing it until the rust is gone, the oil is what seasons it, and never wash it with soap water, clean with a rag and keep it lightly oil and they'll last forever, for really hard baked on food ,put water in it and boil ,that will help remove the food:)

I use Bacon grease and salt on warm cast iron, takes lots of elbow grease, so just keep rubbing and adding oil and salt 'til the rust is gone. I then wipe it off good, re-oil and either put in a hot 400 degree oven for several hours or you can also use your BBQ, I also put it over an open flame when I am camping and leave til the coals are gone. Clean good after seasoning, make a batch or two of regular bread or corn bread and it should be good as new! If it is a griddle, make some pancakes or French toast after cleaning and seasoning, then NEVER leave any water or moisture in the pan, if you are not sure it is totally dry, stick it on a burner or in the hot oven for a bit. This always works for me and I use cast iron every day.

Olive oil works wonders on cast iron!