Using this D2 Racing RS Coilover Kit for your 2010 - 2012 Subaru Legacy is straightforward. First, make sure your vehicle is on a flat and stable surface. Use the separate height and preload adjustment features to set the coilover according to your driving needs and preferences. The 36 - way dampener and rebound adjustability allow you to fine - tune the suspension for different road conditions. When installing the pillowball upper or top mounts, ensure they are properly tightened. As for maintenance, regularly check the teflon - coated threads for any signs of rust or damage. If you notice any issues with the dampening or the overall performance of the coilover, it's a good idea to have it serviced in the US, as it is rebuildable and serviceable here. Always follow safety guidelines when working on your vehicle's suspension.