I think you would need to buy a new tail light and replace the entire thing. If it doesn't hinder the lights ability to work, I'd just leave it. Unless you can get it covered under warranty. My brother's Sentra had a crack that started in the inside of the tail light & the dealership replaced it free under warranty.The right rear tail light in cracked and I assume I have to replace the entire assembly. Has anyone done this? any help would be appreciated.