You can jack the car up, put it on axle stands - fit them at the same length as the originals. Easy.
Ideally to adjust them, put blocks of wood under the car, when it's on a flat surface, then you can adjust the lengths shorter/longer as required.
See this post:
http://www.350z-uk.c...riving-me-nuts/
Or just search on google, doesn't matter what car, the principle is the same.