Quoted from Cenobyte:How do I get that metal pin out of the motor axle so I can connect the small crank arm? I can't get it out and I'm afraid to damage the motor.
Although this may not be the correct procedure it is what I did and it ressulted in no damage.
Lock the axle very securely in a vice, oriented so the pin is sticking upward. Use a hammer to gently tap the pin out the other side.