The blade adapter on a Sears self-propelled lawn mower makes it very convenient to use any blade for any purpose that you choose. However, when the drive belt breaks, there is no simple way to replace it unless you remove the blade adapter. Unless you can get the mower onto a work bench, this activity will take place with you getting onto the ground, and if you are not up to this task, you may want to take it in for some professional assistance.
Tilt the lawnmower up and place each front wheel on top of a concrete block. This will allow access underneath the deck.
Select the correct sized socket for the job, usually 9/16 inch, and remove the bolts that hold the blade onto the adapter. Different mowers have different sized bolts, so choose the socket that fits. A wrench can also be used.
Attach your three-prong gear puller to the edges of the adapter, the prong hooks will hook over the edges, and tighten it up with the center bolt so all the prongs are in symmetrical contact with the adapter.
Turn the center bolt clockwise on the puller using the correct sized socket or wrench. This action tightens the puller but will begin to loosen the adapter.
Turn the bolt slowly but steadily, and it may take a little bit of elbow grease to do this, but keep turning and eventually the adapter will give way and come off.