Easiest way would be a foam ball or cone in a drill motor and a can of aluminum polish.
I have had good luck with plain old Mothers Mag & Aluminum Polish. http://www.autogeek.net/mo5101.html
As long as your wheels do not have the white, chalky corrosion on them that will take care of the problem.
If they are actually corroded and pitted they will need sanding, then compounding, then polishing.. Best done with the tires removed.
Use iron x.