2013 528i Headlight assembly

Where can I purchase a headlight assembly for 2013 528i assembly. Having condensation entering the headlight causing the signal and angle eyes not to function properly. Had the light clean and sealed but it still has a little condensation (in the light) on the passenger side where the signal is located. It's working for now, but I'm not feeling that it will last long. Currently, I have it exposed in the sunlight to dry out. Thanks for any suggestions.