On my bike I restored some pretty bad chrome with just steel wool and polish, I agree heffay that serious rust is difficult to restore though. Take off a seciton, and give it some elbow grease. If there is chrome underneath still, your in business and try to restore the pipes. If not, its probably cheaper to get a set used or on ebay than re-chroming them (I assume.. i've never priced out rechroming pipes, but i've always heard it was expensive).
Rob