To remove the residue, I personally use "carb" or "brake parts" cleaner from the auto parts store. Spray it on, let it sit for about 20 seconds, then scrape the parts clean with a putty knife or a paint stir stick. Do this OUTSIDE as the fumes will KILL YOU. Once the panel is clean, I usually put a bit of gloss black spray around the edges of the panel and any button holes to prevent rust.
DO NOT use a heat gun for the bends unless you are VERY CAREFUL. Make sure your panel and overlay are warm (room temperature of better) but a heat gun will possibly lead to disaster as the inks in the CPO tend to run or the layers of the CPO can separate if heated too much. If you apply it too cold (60 degrees or colder) panels with sharp edges (like Tron) will crack within hours of installation....