you have to jack the car up so you take the load of off the wheel(s). The spring should then have some movement up and down, if not the ride height is set all the way up. There are two plates that the spring sits on, the bottom one (lower perch) is a lock (turn it clockwise to unlock and spin it down a ways). The plate above it (upper perch) sets the height, spin it down to what you think is you desired height. Spin the lower perch snug up to the perch above where you set the height at. Give it a nice tug with the both wrenches. You should have one for each perch. Use one to prevent the upper perch from moving and the other to lock the bottom perch tight against the upper.