i've had a lot of requests for the write up, so here goes. you'll need the coils from a ZJ (Grand Cherokee) that was 4x4 and had a V-8 that was from the 90's i believe, not sure on the years that this works with. clean and spray paint them if you want to, i did mine blue.
chock the opposite set of tires or put the jeep in 4lo and in gear, so it doesn't roll. measure the height from the floor to a common point on all four corners so you can see how much lift you actually get out of it.
start with the front by unbolting the sway-bar at the axle on both sides, uses a torx wrench, so make sure you have the right one. unbolt the shocks at the top from inside the engine bay, works best in my opinion.
on some jeeps the coils are held in place by a retainer with a small bolt on the axle end of the coil, so undo that if you do have it.
get a jack that can go really high and put it under the frame on one side, i used a block of wood on top of my floor jack. jack it up until the coil is loose inside the perches (round things on the axle and frame that the coil sits in). now pull out the stock spring and replace with the front ZJ spring. don't stick your head between the wheel well and the tire while pulling the spring out b/c if it falls off the jack, theres no spring to keep the jeep from smashing your head on the tire, and then there'd be a funeral and no one likes those...
lower it back down and do the same thing to the other side.
leaving everything unbolted, move to the back and undo the shocks at the bottom(easier) and undo the sway-bar. jack up the same way as the front on the frame on either side in the back until the springs are loose. then replace with either the rear spring from the ZJ or your stock front coil. do the same to the other side.
bolt everything back together and check again that everything is good to go.
now measure your spots again to see how much it went up and give it a test drive, taking it out of 4lo of course.
this is just a recommendation of how to do this and i accept no responsibility if you hurt yourself or your jeep or anything else. also, if you don't think you can handle it, get someone to help you or have a shop do it. BE CAREFUL!!! and good luck. post pics of before and after if you got em.