Changing a lawnmower blade is sometimes necessary when the quality of the grass cutting diminishes or after striking an object. The blades are located on the underside of the mowing deck that prevents access to the spinning blade. Whether the blade has been bent or damaged or simply needs to be sharpened, changing a lawnmower blade can be an accomplished with the steps outlined here.
Ensure that the lawnmower is not running and has been allowed to cool completely. Let the unit sit for a few hours if it has been running, as lawnmower engines can stay very hot for a long time. Remove the spark plug wire.
Place a block of scrap wood between the mowing deck and the tip of the lawnmower blade. This will stop the blade from turning when removing the bolt or nut.