I'm sitting here with a new bicycle and an engine kit. The bike has a coaster brake. I apparently have the option of either enlarging the hole in the sprocket or finding a bench grinder and modifying the dust cap. Am I correct on that? So, if I get one or the other done how do I get the sprocket on over the coaster arm? My largest hammer is 3 lbs but I do have an 8 lb chopping maul that I could use as a sledge. Any advice on how to approach this would be appreciated! There seems to be very little information posted on exactly how to fit the sprocket to the wheel. Please use small words and pictures!