There will come a time when your Toro lawn mower is no longer cutting correctly, or perhaps the blade has been damaged by a foreign object. When these occur, it is time to change the blade. Blades have become so reasonably priced that in many cases it is no longer worth the time and hassle to sharpen one. You'll need the make and model number of your Toro lawn mower for the correct-sized blade, along with a little elbow grease to complete this task.
Turn the mower up and onto its side. The blade is beneath the deck, and this function allows easy access to it.
Search for center bolt that secures the blade in place. It is directly beneath the mowing deck on a driveshaft protruding down from the engine.
Wedge your piece of wood between the deck and the blade. By doing this, you are positively stopping the blade from any unwanted rotation, and this action works much like wedging a wrench in the spokes of a bicycle.
Place the box end or closed part of the wrench directly onto the center bolt, and make sure it does not slip and is firmly in place. The size of the bolt will vary from mower to mower, but generally it will either be either a 9/16- or 5/8-inch size.
Turn the bolt counterclockwise. A little elbow grease may be necessary because these bolts are tightened firmly and some muscle must be applied. Don't be afraid to use some pressure to get it turning.
Turn the bolt once loosened until it falls off in your hand. If the blade does not fall off with the bolt, tap it gently and pull on it to remove it from the mounting spindle. Remember how all the washers came off because they must be put back on the same way they came off.
Reverse the procedure and replace the blade in the same way that it it was removed. Tighten the bolt firmly, pull out the piece of wood and set the mower back down onto its wheels.