How should you change rim colors if it was sprayed with Pylox or ordinary spraypaint?

Hi guys, I bought a 2nd hand vehicle and the rims of the tires were spray painted by the previous owner using Pylox. It now looks old and faded. I am planning on having it repainted or restored when I saw Plasti Dip on Facebook and now I am looking forward to trying it out. I would like to know if I should have to remove the old paint like sanding it or should I just clean it then I can have it painted using Plasti Dip?

Or should I just bring it to a shop who specializes in restoring rims/mags?

Thanks in advance for any replies! :)