Jimmy, please don't apply impacts to the sprocket if it is connected to a gear train - you are likely to damage a gear. If the sprocket is directly on the axle of the drum, it is likely to be either screwed on, or lightly pressed on over a key, but if there is a gear set inside the drum like on the Scott Bonnar 430 and 590, there will be an obscure way to dismantle it without damage.
