Hi Al,
I was just going through the same thing yesterday. Well, almost. I wanted to move the right springs to the left and left to the right. I jacked up the frame and supported it on stands, then put jacks under each spring pack to get them to the right point where the shackles were centered in the spring and hanger eyes. It takes some finesse to get them just at the right point where they require the least effort to R&R. Penetrating oil may help. My issues were trying to align the u-bolts with the lower shock mount plates while the axle was wanting to rock'n roll all around on the floor. I was thinking...someone on the 3A page ought to do a write-up on exactly how to R&R springs. Fortunately, after a day of screwing with this, my fridge keeps beer very cold!

I know this is of little help, but you are not alone.