Originally Posted by azn370z

For the rears what you need to do is remove the stock strut and spring
Take the spring seat collars and set them at the same level not tightening them yet
Put the springs on, put the tires back on and bring the car to the floor
See if the height of the car is the desired height, if not then raise it back up doing the prev steps
(be sure to keep the height about 1/4" higher than what you want as you still need to set preload)
Once you have achieved the height you want, raise the car back up, take out the springs and spring seats
tighten the collars on the spring seat and reinstall (if you try to tighten them while on the car there is a possibility you can strip them)
You should have a bolt that goes through the factory lower arm and bolts to our spring seat, at this point tighten that too
Take your spare jack and place under the hub raise the hub so that the spring sits snug but not compressed

Now install the strut, tightening the top only
Measure the distance from the center of the hub to the fender
Raise jack 1/4" creating the preload on the spring
Scroll the lower mount of the strut up so that its level with its mounting bolt, slide the bolt through it and tighten
At this point you should have the spring preloaded 1/4" and the ride height at your desired level.