It's easy to do. First you need a hydraulic press....even a small one will do. Then you lay the main leaf down on the garage floor and draw the shape of it so you can use that as a guide to see if you have returned the spring to the original shape, except with the eye reversed.
Then scribe lines across the face of the main leaf every inch so that you can uniformly bend the leaf the opposite direction. Put the spring into the press with a couple pieces of steel acting as supports (spread apart about 4 inches or so) then start putting pressure on each of the one inch marks, just a little to each one. You don't need to make much of a bend in each segment to get the spring to reverse, just a little bending at each spot will do the trick and not kink the leaf. We found that about two pumps on the handle of the press were enough in each spot to do the trick. We counted each stroke so the we knew the pressure was the same across the face of the leaf.
Keep comparing the leaf to the drawing you made to see if it is uniformly bending back to the same shape. You might have to touch it up with the press in a few spots to get it perfect, but if you take your time it will end up correctly curved. You may have to shorten the second leaf a little on each end because it may now hit the eyes. We used a bandsaw and it was tough cutting, those leaves are very hard. You can also put less curvature in the main leaf and get a flatter spring when all is bolted back together.
Two guys make it easier, one holding and pumping and the other one feeding the spring into the press.
Don
