Try and sand the rust areas smooth. Then repaint, probably black since it will be hard to get an attractive brass paint. But you can do brass if you find a finish you like.
That is all there is to it.

roxyl: I have not done it yet, but got info from really great people on here to use stain. Sand lightly and them apply a dark stain (wipe one then wipe off) if you want that popular bronze look.... then apply a top coat (varnish). I bought a chandy on ebay -a wonderful bright gold shinny finish.... yuck! I am going to do this after christmas.... can't wait. I am using the same stain I have used on my garage sale coffee table.... it is beautiful. Just my 2 cents worth.

oops.... wipe on not one... sorry my typing skills are not what they used to be.