My experience with removing a bushing is to use what a Plumber calls a Star Wrench. You will probably lose the bushing but the idea is to tap the pointy Star Wrench into the bushing and buggering up the threads, then turn it out counter clockwise with a wrench. This assumes the bushing was initially screwed into the platform.
Well, Bruce. If I understand Ken's predicament, it is not screwed in; otherwise, since it is turning, it should screw out. Right?