Using this grille is easy. First, gather all the mounting hardware that comes with the grille. Then, carefully remove your original OEM grille from your 2018 - 2021 Subaru WRX or STI. Next, take the new JDM - style grille and use the provided hardware to attach it firmly to your car. Make sure all the screws are tightened properly. As for maintenance, regularly clean the grille with a mild soap and water solution. Avoid using abrasive cleaners that could scratch the surface. Also, check the mounting hardware from time to time to ensure it's still secure. If you notice any loose parts, tighten them up right away.