What's the procedure for removing leaf spring rubber bushings etc? Tried heating a hammering out with a drift but no budge. Do they have to be pressed out?

 

They have to be pressed out if you want to replace the entire metal-rubber-metal bushing.
On the one I just replaced, I hammered out the bolt which had the inner bushing stuck to it. Then I hammered the old bolt out of the bushing then hammered the old bushing back into the rubber and installed the new shackle bolt and shackle. I think this is what most shops will do because the leaf spring has to be removed in order to press the bushing.