My fins on my 03 were very pitted. I just purchased a mini belt sander on ebay. $49.00. So far I used the medium belt and then the fine (120 grit). I am buying the polishing belts next. So far it looks good, but you will lose the factory machining look. Mine should be very smooth when done. I can reach the left side easy. The right is a little more challenging & you will have to remove the horn and air cleaner.

 

On a cold engine spray down with Simple Green then hit it with a pressure washer and then have at with Pig Spit or spray silicone...they are one in the same.