If you don't have access to a press, you can use a piece of threaded rod and washers. Double nut one end, then washers, then threaded rod through the bushing, then a short piece of pipe or large socket followed by another washer followed by another nut. Are you picturing it yet? As you "tighten" the single nut, you draw the bushing through the trailing arm and into the socket or piece of pipe. Just make sure the pipe or socket is larger than the shoulder of the bushing so that it doesn't become an interference fit into it.
Or... the quick and dirty way if they are rubber is to use a torch and burn them out. quick. dirty. smelly.
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