If your desire is to get them to look like polished chrome, then you will be disappointed because the high magnesium content of the cast alloy prevents such a look. However, you can come close if you use 500-grit wet-or-dry sandpaper to remove all traces of the machining tool marks, then polish like mad. Coat with high quality paste wax; it will make the inevitable repolishing much easier. Caswell Plating had a ton of excellent low cost tools and supplies...I highly recommend them as a source.
Of course, doing this with the wheel off and stripped of brake rotor disc makes it a tolerable job. Run a metric tap in all the rotor disc mounting screw holes to remove the old Loctite. Reinstall with blue or purple medium strength Loctite.