Not an expert, but, when you have anything polished the first operation is to Mop the item. This is a course fabric (possibly calico) wheel with a course soap that will give a satin finish whilst buffing out deep scratches (and letters). At this point it will look really nice and race.
Normally the next stage would be to use a finer wheel and soap to polish to a mirror finish.
All that said, I'm assuming that the standard can is stainless steel .... if it's mild steel with a protective coating then any type of buffing etc will remove the coating and the can will go rusty
