You have to remove the sprocket from the shaft on the front of the engine first. Afterward, you'll see a 6x1.0 bolt with a 10mm hexagonal head on it with a washer that holds the bushing and the shaft in. The washer is what sits in one of the flat edges of the bushing to keep it from spinning around. Once the bolt is removed the assembly will slid out. You may have to use a dead blow hammer to knock the bushing out of the block from the rear due to carbon build up on the rear side of the bushing that is exposed to oil and crankcase vapors.