Side Panel Dye

I bought some rear side panels on Ebay for my Barracuda. They were originally black but were dyed white. I would like to dye them back to black. The dye has some flaking. What is the best way to remove the flakes and prep the surface for the new dye. I heard it's a 3 step process. Cleaning, adhesive spray, then the spray dye. Do I need to go over the surface with a scotch pad first? Thanks.
Author: money pit