Step bars are a great way to add style and function to your vehicle, but they can be difficult to keep clean if you don't know how to clean stainless steel step bars in the first place. To clean the side step bars, you will need a microfiber cloth, dish soap or a stainless steel cleaner, and some elbow grease. First, dust or dirt off the bars with the cloth. Then, using a circular motion, work the soap or cleaner into the surface of the bar.