Great pic. I used a 3 inch cutting wheel to do the same. Here is how I handled the leaf bolts and shackle bolts:
I finished the install of new leaf springs and extended shackles.
Front leaf bolts: Side 1: Broke the weld, cut the bolt on both sides w/ sawzall--recommend Irwin or Dewalt bi-metal blades, lots of gruntwork.
Then took a 3 inch cutting disk and made 4 cuts in the pocket on the out side of the unibody, just like the picture that is posted on this forum. Side 2: Cut the bolts both sides, then made the cuts in the pocket. Mistake as in the rear bolts was not breaking the weld before cutting the bolt. Then used new bolts and nuts from the dealer ($6 per). I couldn't have done it without help from this site.
Upper Shackles: I drilled a small hole in the pocket below and applied PB for 3 days and still no luck. Side 1 as I thought the nut broke the weld and was spinning free. I could trun the bolt freely once this occured, but the bolt was still locked up on both the sleeve and the nut. Solution: I cut the leaf bolt using a sawzall on first the inside and then out side. I removed the rear bumper--8 bolts-- widened the exsisting access hole using a 3 inch cutting disk to allow a socket head to reach in, and used a new jeep bolt and nut to secure. I had to use 4 washers to take up some of the bolt since it kept pushing my socket off and the access space is too small for a deep socket. Side 2: I hadn't really torqued on this side yet, so thinking it would be easier not to break the nut weld, I just cut away on the leaf bolt. After the inside cut was made, the bolt slid free from the sleeve without need of a further cut. Now the only problem was that the nut and piece of bolt were still blocking the way. I got it off with an airchissle from the inside (bumber removed) without too much trouble, but would just try to muscle it out next time by breaking the weld nut before cutting the bolt. That way if the nut breaks the weld it easier to get out, and who knows it might have come out. But the rust on the end of the bolt looked substantual and probably wouldn't have come off.
Thanks and hope this helps someone else in the future.
The Jeep dealer said they had never seen that problem before and didn't have any advice. Traitors!!!