I haven't replaced the bit you're talking about but I've had the shifter off to get at the brake shift interlock. There is a set screw on the handle, pointing at the driver's seat, loosen it with a small allen key and you should be able to slide the handle up off the shaft.
The trick is, the O/D off switch (in the handle) has wires that run down into the shifter. As I recall, I was able to pull firmly but gently enough to raise the handle clear of the shaft without disconnecting the O/D wires, but it felt really tight.
Once the handle is off the shaft you should be able to take of f the whole center console, don't forget the screw(s) inside the armrest/CD holder.
Good luck.
