I've done a ton of superduty leaf springs. Just about every set the bolt is seized in the shackle to frame bracket and I always just torch through the eye and bushing and inner sleeve until they come out. They are horrible stinky, especially inside a building. The under bed winch idea would be good if you can get the cable straight out the back without the crossmembers and stuff in the way. I was picturing above or through the bed with the cable ran across the floor and out the back but then its all in the way of other uses of the bed.