Exact fit part, no problem there. Plastic gear teeth engaging with metal flywheel teeth is an odd design but mine lasted over 15 years. Need to remove some engine cowling to get to the starter bolts. C-clip ring holding the top cap on the pinion gear assembly is tricky. You'll need to apply enough downward pressure on the top cap to flatten the spring washer underneath while prying the C-clip out of the groove it sits in. Do this before loosening the starter motor from the engine. Pinion gear is a quick swap out but pay attention which side is up when disassembling. Maybe mark the top with a Sharpie before removal. Once new part is installed, probably better not to lube with anything heavier than WD-40, if at all, as gear needs to slide down the spindle quickly once the engine turns over. Button it all up and go cut some grass.