The crush ring can be frustrating to install as the interference fit can be very tight. If you examine your crush ring you will see that one end of the cylinder is slightly rounded, this is the side that should face up towards the knob.
You will also see that the metal corrugation of the ring is wound in one direction. When you are installing the knob you will find that it is easiest to push the knob on in with a twisting motion, make sure that you are twisting in the same direction as the spiral. IE. "When looking at down at the top if the crush ring is circling the shifter in a clockwise direction, then install with a clockwise twist".
When installing the knob leave an eighth of an inch of the crush ring above the end of the shift lever. I then lock a small pair of vise grips on to the shift lever at the base of the crush ring to keep it from sliding down as the knob is installed.
Once the knob has started to fit onto the crush ring/shift lever you can take off the vise grips and push the knob the remaining way onto the lever.
(I also have written a 25page pamphlet on how to put on your pants one leg at a time.)