I use two c-clamps, one on either side of the center bolt, and release them about 1/2 turn at a time, alternately. Buy a new center bolt which will usually be several inches long, and use it to compress the leaves as you reassemble the spring pack. A little anti-sieze compound will help keep from stripping the thread as you tighten the nut on the center bolt. Once the spring is fully reassembled, cut off the excess length of center bolt and peen the end of the thread to keep the nut from backing off.
The fun part is doing all of the above on tractor-trailer springs designed to support a 40-ton rig! I'd disassemble/reassemble them in a hydraulic press!
Jerry
