There is one thing that I would reccomend doing before painting. Sand the reflective coating and primer it. This will help the paint adhere better, and keep it from chipping. You may also put a clear coat on it if you choose to do so.
Follow directions. But, my one recomendation would be to leave some silver in the corner. It seems like people either paint it entirely or not at all. With 5 min of masking, it looks way more oem, to me atleast.