Its easy enough.... Just remove the bag from the machine, and then you will see one screw to the plastic cover over where the cord plugs in to the motor. With that screw removed, the plastic cover can removed by levering it from the side using a flat blade screwdriver.
If the cord is broken it is invariably at the point where it joins the handle and bends as it is wound up, or at the point where it joins the machine at the bottom of the handle. It bends there as the handle is moved back and forth. There is of course the one screw to be removed at that point and that is it, the cord will pull off from the handle.
GJ
June 2011