installing a new blade

the blade is attached to the engine via an adapter and a bolt that holds in onto the crank. Use either your own strength, or have someone hold the blade while you loosen the bolt on the bottom. You can also use a block of wood between the blade and the deck to prevent the blade from turning.Be careful that nobody gets hurt, use gloves or a rag to hold it. The tool to use would be either a box wrench or a socket. Sometimes those bolts are pretty tight and may require some extra torque to loosen. Hope this helps.