Lisle tools sells a handy looking tapered screw that bites in to the bushing, then you put a grease gun on it to force it out. I think I will get one one day. Could be a little less messy than the grease and hammer, and perhaps quicker.
I have had good luck with the tap, but once you have threads in the bushing remove the tap and use a bolt to jack the bushing out. Or a slide hammer on the bolt.
Grigg