We have at least one place in the greater St. Louis Mo. area that refinishes all types of OEM and aftermarket wheels. They advertise on local TV station and radio and claim a 3 day turnaround.
I'd be surprised if there is not a similar business in your area.
You could do it yourself, but you will not get an 'as new' finish. There are aluminum paint strippers you can buy in a spray can at the autoparts store and then you might try Flitz or Neverdull. Regardless, if you try it yourself it's gonna be a lot of work.
