The video method of changing the Blender Drive coupling DID NOT work as it simply spun to freely. Read further on this blog about other people experience and followed the lead of removing the bottom of the unit using the screws under the feet pads. Grabbed the small knurled end of the central shaft with vise grips and repeated the hammer and screw driver method of loosening the drive coupler. Worked with a very slight tap. Re-assembled and all worked well.