Take a drill with a 3/8" bit and swiss cheese the crap out of the rubber in them. To the point where the round part in the middle, along with the rest of the rubber, will fall out.
Then I take a chisel and on the side with no lip, knock the ends inward all the way around.. so it looks like the metal housing for the bushing is collapsing inward. Then on the other side where the lip is, use a dull chisel or something similar against that lip, and a mallot or hammer and whack em out... if you want you can put a little heat to the axle ears where the bushings go through... might loosen it up some... then knock em out.