First, pull on a pair of gloves and use some steel wool to brush away any loose or flaking rust.
Then, grab an old towel. One that you definitely don't need again. Put the towel in a bucket and saturate it with some plain white vinegar.
Wring the towel out just enough so it's not drippy and lay it over the rust. This is a nice method because it contours to the piece you're working on.
Let it sit for twenty minutes or so. The acids in the vinegar will loosen the rust from the piece so you can easily clean it away with some steel wool.
After twenty minutes remove the towel and use the steel wool to clean away any remaining rust.
Once you've got all of the rust removed wash the piece with some clean water to remove the vinegar.
Once it's completely dried you'll be able to either poly the bare metal or prime and paint with a rust resistant paint.
An all natural and inexpensive rust remover! I'm Mrs. Fixit and it's just that simple!