Going off memory, I think the CJ front perches are 2" wide and 28" apart, and the rears are 2.5" wide and 36" apart. So, it sounds like you will need to remove them, cut them smaller, and re-weld them in the proper place.
I've never relocated spring perches, so I can't comment on the best way to do it. I'd probably mock everything up, with axles, springs, and driveshafts in place, then weld the perches where they need to be.
Perhaps CSP, or others with experience, will chime in with a better approach.