I removed 3 from the front of my truck. I have had no problems, but I started with a new spring pack. I was just after a softer ride and didn't pay any attention to how much it lowered it. It won't be as much as you think, since each leaf is only 1/4" thick. It will drop more than that depending on how weak each leaf is. Start with the shortest ones. The more you take out, the softer the ride will be, BUT, take to many out and you could cause problems. The springs will act springier with less support under them, and under hard cornering or stopping you could get out of control very easy. You will also, need a stiffer shock to control some of bounce you added!
If you really want to lower it, go with a mono-leaf spring made for what you want. If you are after a better ride and a tad lower, pull out a few leafs.
Its a easy job once you have the spring out of the truck. Just one bolt in the center holds the pack together. Use a large C-clamp to hold the springs and remove the center bolt. Most of them will need broke off or cut off! Then loosen the clamp and let the pack loose. Now would be a good time to clean and inspect the rest of the group. A good local trailer shop or spring shop will have new center bolts. I used a Allen head bolt in mine. Just make sure the bolt head fits the locater hole in the axle. Joe