I put my jack stands in front of the springs to support the body (not the axle). To save the body from damage, I used a 2x4 as long as the width of the body so that - if you can picture it, from floor up - jack stands under lower lip of body on either side - 2x4 stretching across width of car in between jack stands and lip of body. I then supported the pumpkin of the rear axle with my jack - undid the shackles (I was able to undo the plate themselves that attache the rear shackles to the body) lowered the whole unit and went to town.
hope you can visualize that?
If it's not working visually, tomorrow I'll be using the same technique to add the spacers to the front of the springs if you want to wait for pictures.