Remove any surface grease and grime with a household cleaner/degreaser, such as 409. After spraying the surface, wipe it off completely with a clean rag. This will remove any foreign substances that will get in the way of the cleaning and refinishing process.
Remove the rust from the surface of the object by rubbing it with a steel wool pad. Remember that you are only trying to remove the rust and not actually trying to remove the surface of the object itself.
Remove the deep-seated rust from small crevices and weathered areas by spraying some WD-40 on the area, allowing it to penetrate the rust for a few minutes, and then going over the area with the steel wool until the rust is gone. If you get too much WD-40 pooled on the surface of the object, wipe it off with a rag.
Protect the freshly refinished surface. Using paste floor wax, apply a thin coat of wax to the surface of the object in small sections with a rag. Allow the wax to dry (approximately 15 to 20 minutes), and then buff it to a high-gloss shine using a piece of cheesecloth. Repeat this process until you have three coats of wax.
Perform periodic maintenance on the cast iron object in order to keep it in refinished condition. Clean and re-wax the object on a monthly basis if it is heavily used. Otherwise you can maintain your cast iron surface on a quarterly basis.