Scrub off rust and loose debris with steel wool or a stiff brush
Wash the pan with hot water and a small amount of dish soap
Rinse thoroughly and dry completely
Remove stubborn rust with a paste of baking soda and water or white vinegar
Wipe the pan clean and dry again
Apply a thin, even layer of cooking oil all over the pan
Place the pan upside down in an oven at 450 to 500°F for one hour
Let the pan cool in the oven
Repeat the oiling and baking process 2 to 3 times
Store the pan in a dry place
Wipe a light coat of oil on the pan after each use