Leaf spring bushing removal question

I used a butane torch just enough to get the rubber soft again(softer the better really but too much heat on a spring might be bad) and then air chisel to finish knocking the rubber out. On the bushing sleeves I very carefully cut them using a saws-all making sure not to get into the spring itself and then either a manual chisel or air chisel, just need to get the corners up enough to "shrink" the sleeve and it slides right out.