Using this D2 Racing RS Coilover Kit for your 1990 - 1995 Subaru Legacy is easy. First, make sure your vehicle is parked on a flat and stable surface. Then, follow the installation guide that comes with the kit. When adjusting the height and preload, do it gradually to find the best setting for your driving style. Remember to check the tightness of all the components after installation. As for maintenance, keep an eye on the teflon - coated threads to ensure they are free from rust. If you notice any issues with the dampening or rebound, it can be rebuilt and serviced in the US. Regularly clean the powder - coated aluminum mounts to keep them in good condition.