Using this OLM F1 NB+R V2 Final Edition rear brake and reverse light is a breeze. First, locate the area where your old rear fog lamp is installed on your 2015 - 2021 Subaru WRX/STI. Remove the old lamp carefully. Then, take out the new lamp from the package. You'll find a plug - and - play harness. Simply connect it to the corresponding ports on your car. Use the included mounting hardware to secure the new lamp in place. When it comes to maintenance, keep the lens clean. You can use a soft, damp cloth to wipe away dirt and grime. Avoid using abrasive cleaners as they might scratch the lens. If you notice any loose connections or issues with the light, check the wiring harness connectors. Make sure they are firmly attached. Also, store the product in a dry place when not in use to prevent damage from moisture.