Pretty sure that's cooorrectomundo. Been a long time, but it sounds logical anyway.
Not a lot. Does not need to clamp anything tightly. Just there to keep excess movement at bay.
In fact, the helper does not need to put much pressure downward on the wheel. Just enough to close most of the gap, and put a little pressure on the spring. In a perfect world, the upper components won't be able to push down so far as to contact other stuff (like the shift collar), but I've heard of cases where pushing down too far caused them to rub against one another.
No rubbing allowed!
So push down gently but firmly, then push upward on the clamp just so that it's in contact with the lower bearing and washer/seal/thingy.
Tighten bolt pretty firmly (but again, don't go all GI Joe with kung fu grip on it. Just firm...
That should do the job nicely.
If you feel like there is play when you push down on the steering wheel after that, do it again but slide things up tighter. If you feel like it's too tight, or anything is rubbing, lessen the tension on the clamp.
It's probably got scientific and engineering tolerance and torque values, but it can be done "by feel" just as well.
Paul