If the current powder is a translucent then use a good chemical stripper to remove the powder and you are good to go. We use B17 industrial chemical stripper to remove powder but aircraft stripper will work ok it will just take longer. Do not media blast the wheels unless you are planning to have them recoated other wise you will rough up the chrome under the powder. If the current powder is a solid (non trans.) color then the powder coater should have put a light blasting profile on the chrome before coating the wheels to give the powder a better profile to adhere to. If this is the case then you will have a very dull finish on the chrome after you strip them and they will need to be refinishes anyway. If you are wanting a chrome finish then take it to a chrome shop to have them re plated please don't go with a powder "chrome" as it is no replacement for real chrome. I only use the powder chrome in my shop as a base for candies or if the customer just like the look of the chrome powder and has to have it. If you have any questions I will be happy to help.