Remove electrical components and clean the plastic thoroughly with household cleaners. While wearing rubber gloves and eye protection, brush/apply a liberal amount of Retro-Brite to yellowed area. Mask colored decals with electrical tape. Place in plastic bag or wrap in plastic wrap.
Place covered area(s) in direct sunlight for 8-12 hours (temperature of 40°F or above). Periodically check to ensure Retro-Brite covers all yellowed areas. If not, redistribute or add additional Retro-Brit
While wearing rubber gloves and eye protection, wash and dry components. If desired whitening effect is not obtained, repeat the process as more exposure to sunlight will continue to brighten the plastic.