Try an abrasive scrub pad or steel wool...if it's really bad, you might need small grinder. Once you get the rust off, though, make sure you paint it with a rust-proof paint or primer so the rust doesn't come back.
Try some CLR spray (Calcium, Lime, Rust)...it will bubble up, and you can get it off with the rough side of a handy sponge.
would it be okay to spray paint? i think it would give it a finer finish then apply the rust proof treatment afterwards?
You can get the rust proof in a spray paint- look for Tremclad.
thank you <3