either heat the spring or cut a coil as long as the spring doesn't taper in on the end. generally cutting a coil will give you around a half to an inch of drop. cut a half a coil, put it back together and then see how low it sits, if you want it lower, cut some more. also cutting coils increases spring rate but from my experience it isn't a noticeable change. if you cut the coil too short you might have to use wire ties to keep the coils in its seats.
if you don't feel like taking it apart just heat a section towards the end coil red hot, you'll see it drop. it will essentially make the loop a "dead" coil, basically the same effect as cutting a coil off.
don't be afraid to do either of these things even though alot of people will claim its dangerous.
i've had 2 camaros with cut coils, a 67 chevy with heated coils, a 82 s-10 with cut coils, and a 81 bmw with cut and heated coils. never once had a problem and they all were daily drivers.