An orthopedic cast removal tool and method uses an unmodified, typically cordless, rotary impact driver and a embedded wire to cut through an orthopedic cast for removal. By merging it with a slotted spacer block specifically for this cast removal purpose, an ergonomic tool is provided which allays fears of orthopedic patients. When rotating and encountering high resistance of the plaster or fiberglass material of the cast, the cordless rotary impact driver does not bog down since it seamlessly engages impact action, which offers an order of magnitude or more torque multiplication via short frequent pulses (several per second) to overcome this torque resistance. Thus a high amount of torque with very little reaction force is made available to cut through a cast while affording the technician good control. The cast is cut very rapidly with little dust creation and no jostling of the patient.