How to replace a lawn mower wheel

Wear work gloves to protect your hands.

Lift the mower and slide a block of wood under the housing to support the mower with the wheels off the ground.

If the mower is heavy, have a helper lift the mower while you position the block of wood. 

Use a slot screwdriver to pry off the hub cap.

Remove the nut that secures the wheel to the axle shaft and slide the wheel off the shaft. If the nut has a washer, remember its location.

Use a clean rag or paper towel to wipe debris off the axle shaft, to prevent the new wheel from binding.

Install the new wheel on the axle and secure in place with the nut. Attach the hub cap, if there is one.

Remove the block of wood from under the mower.