I did wonder if I could move the shift lever by hand when detached, but I was worried I may mess something up. That's very good to know.

It wasn't really difficult to slide out by hand, but we weren't exactly treating it like a delicate flower either. If you have to put that nut on after the two pieces are together, how do you torque it? I remember it being a huge 12 point nut. Even if I remember wrong, I've never seen a crowsfoot wrench that big...