How do I take the blade off a lawnmower and put it back on?

Righty tighty, lefty, loosey. Remove the spark plug or unplug the electricity and block the blade from turning. I use a block of wood, the apply the proper size wrench to the bolt head in the center of the blade and remove it. After the bolt is out, tap the blade end with the block of wood and it should fall in your hand. If it is a gas mower, the oil should be changed about the same time as the blade needs to be removed for sharpening. There is a drain plug located on the underside of the mower, remove it and the oil will run out.

This how it is done on the most common rotary mowers. If it is a lawn tractor or riding mower, it is best to read the owners manual. For a reel type mower, the blades are not removable. Tipping the mower on it's side may get oil in the cylinder and this will need to be removed before it can operate.

To put it back on, reverse the process, the cutting edge should be on the leading side of the blade.

First up, be prepared for some skinned knuckles. It's best if you can get the lawn mower up on to a bench. You will need a ring spanner and a socket spanner. Place the ring spanner on the top of the bolt holding the blade on, and use the socket with a ratchet on the bottom one. You may need some assistance to hold the blades steady. Simply reverse the situation when replacing with new blades.

Do Not tilt the lawn mower on its side, as this will let unwanted oil into the cylinder.

Be Sure to disconnect the spark plug before you start. This is to ensure that it will not kick over and take a few of your fingers off.

Good luck.

1) Remove the spark plug wire off the spark plug

2) Either put mower up on bench or tilt mower back to access mower blade

3) Use a 2 x 4 or vice grips to stop blade from turning

4) Use proper size wrench or socket to remove blade

5) When installing a used blade it is important that the blade is balanced

6) Install new blade and make sure the sharp edge is closest to the ground

7) Tighten blade to about 40 lbs. by wrench or hand

8) hook up spark plug and your ready to go!