The Collet is the best neck die for factory rifles made today, IMHO. It does have a moving part so some folks have difficulty with it.
Disregard the instructions. Put a case in the ram and push it up, repeatedly, while slowly turning the die down a small fraction of a turn at a time. When you get the proper neck tension to hold a bullet, takes about 20# of lever pressure, depending on what press you have, you're done. Further pushing will do nothing more to the neck but you can damage the die by excess pushing and striping the aluminum top cap out. (It's made to do that to prevent the ham-fisted among us from damaging their press!)
Understand Lee's collet die DOES NOT produce the tight neck-to-bullet fit a conventional size die does. That's to prevent us from bending a straight neck with excessive seating force, which is a common occurance with conventional sizing dies that are frequently excessively smaller than bullet diameter.
There is only one way to crush a case neck/shoulder in that die. We can go wrong by giving the die a "dry push", with no case, and get the collet sleeve jammed stuck into the upper part of the die. THEN, with the collet fingers jammed shut, necks will get pushed back. If that happens, disassemble the die and free the collet, then all will be well. Just don't push the collet up without a case again! AND, while you have it apart, lightly grease the cone-shaped top of the collet for easier work.