Dan,
I am not sure which bolt you are talking about.. I can't access your webshot...But...I just took my springs/rear off the truck. To remove the rear shackles, remove the bolt that holds the shackle together. Knock the shackles off. The bolts that go through the frame and spring are threaded. They will screw out if you keep the shackle on one end or the other..
What worked for me...
If you have not done so, I would recommend replacing the bushings while you are this far torn down. Mine were worn all the way to the frame eye and the bolts were worn half through. On one side, I was able to leave the bolt in the frame bushing and drive it out with a large hammer. On the other side, the threads were worn away and the shackle bolt just flopped around in the hold The bushing would not budge..I had to saw, chisel etc the bushing until I collapse it enough to drive it out.
While you are at it, check your front bolts. Again, mine were half gone and my truck seemed to be well maintained....
If you are talking about the non-shackle end of the spring, nut on one side, threaded bolt. Impact wrench took it out nicely.
Is this what you were looking for?