Removing a lawn mower blade to replace it or sharpen the blade should be a quick process. But when the blade is stuck, the process can be a nightmare. To remove a stuck lawn mower blade, you need leverage. A breaker bar is a longer handle for your socket wrench. The extra handle length can give you the leverage you need to loosen the stuck blade bolt and remove the blade. Breaker bars are available at home improvement centers.
Grab the spark plug wire by the boot that covers the spark plug and pull the wire off the spark plug.
Siphon the gas out of the fuel tank into a gas can with a manual siphoning hose.
Lift the fuel tank side of the mower and rest the mower on its side. Wedge a scrap piece of wood between the mower blade and the mower deck so that the blade will not move.
Spray the bolt that secures the blade to the mower with penetrating oil. Spray the bolt liberally and allow the oil to soak for two hours.
Place a correct size socket wrench over the head of the bolt. Attach the breaker bar to the socket. Hold the head of the socket and breaker bar with one hand and loosen the bolt using the breaker bar as the socket wrench handle.
Pull the breaker bar and socket off the bolt when the bolt is loose. Unthread the bolt by hand and remove the blade from the mower.