There is a spring bushing puller Tech Tip for removing the bushing from a spring perch. I found the 3/8" bolt to be too small a diameter (I quickly/easily broke two bolts), so I used a 1/2" bolt (after a little grinding of the head, to allow it to fit inside the bushing journal in the perch). Works like a charm - simple design, easy to use, and effective.

I do not know how to get a bushing out of the spring eye. My springs are new, with new bushings. Maybe someone who has done this will offer suggestions.