The portion that bolts to the rear trailing arm should be able to come out by hand, or possibly a flat head screwdriver. The portion that bolts to the chassis will require some needle-nose pliers. Seeing is how that side has a circlip, it will require the use of needle-nose pliers to pinch the two points together so the clip will slide off. Then you can pull the bushing out and slide the clip back in once you have replaced it with the new ones.