I worked in a metal shop for a number of years. A friend of mine there was an expert at polishing metals, and I learned the basics from him. First piece of advice is that the FJR mufflers are not cheap, and you'll need to be careful that you don't do more harm than good. Getting a mirror finish on them is possible, but will take patience, time and careful work, and it's a messy process. The pro's use power equipment for this, either a buffing wheel on a large pedastal grinder or a buffing wheel mounted on a 7" grinder. Use much less than that and it will take you forever to get done. You will need "rouge" or polishing compound, to lubricate and aid in polishing. It comes in solid bars, and you hold the bar against the buffing wheel which will then take up some material. Keep the buffing wheel moving, and DO NOT allow heat to build up in the part you are polishing. In the case of a stainless muffler, holding the buffing wheel in one spot could easily heat the thin skin of the muffler and create a burn mark that you might not be able to remove. Stainless is hard material to polish, unlike aluminum and most steel, so it will take a lot of work. Once the polish job is completed, you will easily be able to clean the mufflers and restore the shine using non-abrasive cleaners and polishing products. Note that scratches and defects will be much more noticable on a highly polished surface, as compared to a matte finished surface. Happy buffing!