Yes, the shifter is on very tight, but it is extremely easy to remove the nut. Take two wrenches and place one on the shaft and one on the nut. With the other ends about 1-3 inches apart (considering the lefty loosy rule), clamp one hand down on both at the same time. It's a snap.
By the way, when the directions say don't tighten the rings screws too much, there was a reason. One of the nuts on mine was already stripped, and I had to fiddle with it to get it to hold. That was a pain because to get to the nut, I had to take off the ring and all other 5 nuts twice!