Ideas for removing a jack hammer bushing.

I have a skid steer jack hammer that I need to replace the bushings and pike. I have the every thing except the bushings out. I have tried a slide hammer to no avail. Next i made a plate to fit behind the front bushing with a nut welded in the center with a piece of 5/8 all thread through the bushing and through a plate across the front of the hammer with two jack bolts to no avail. Any ideas?

Ideas for removing a jack hammer bushing.