First measure from center of wheel hub up to the fender lip, straight up as shown. Measure and write down all four corner measurments. Why from the center of the wheel? That's the way we do it, so the wheel/tire selection is not an issue, and we can use those dimensions to measure suspension travel witth the springs out of the vehicle. Determine what corners need to go up or down. Our front measured 11.75" and we want 12.25" so we need to raise the front .50".
Loosen the lugs slightly and jack up the first corner that needs adjustment. Put the jack stand in place for safety. Loosen the perch nut using the 3/16" Allen key. There's no need to remove the 1/4" socket head. To raise the corner, raise the perch nut, pressing the spring upward. How much do I need to adjust? Each full turn is 1/16" movement at the coil-over, but the change in vehicle height will differ with the platform, because the motion ratio of the suspension varies. So 3/8" change at the coil-over is 6/16" so that is six full turns of the perch nut.
Now for the fun part. It's time for a road test! Tip: drive a regular route that you know, the route to work, school or home, so you can compare the change in ride quality and handling before and after the ride height changes. Note that after height changes greater than 10-12mm, the wheel alignment should be checked. The toe-in/out will be the most significant change on most FWD platforms. Proper ride height settings are a huge step toward a solid set-up and maximizing ride and handling.