To free the wheel, so that it won't turn when OttO turns the rudder, one grabs the collar and twist the top of it to the left in the picture (to port). There is a small click as the pins get around the curve of the "J" and then the collar can slide aft on the shaft a distance a bit bigger than the thickness of the wheel's hub. In the picture on the left, the collar has been moved aft.
Now that the collar has been freed from the wheel, the wheel is free to slide aft along the shaft. In the picture below you can see the wheel in it's "free" position. In this position the wheel sits still and the shaft is free to turn within it. The key, which normally locks the wheel to the shaft, has been attached to the shaft so that it can't fall out and it has been modified with a "V" on the aft end (facing towards the wheel) so that one can push the wheel forward on the shaft more easily to re-engage the wheel.
When we pull when wheel back and let OttO drive, I'll tie the wheel so no one accidentally pushes it forward or tries to turn it and it spins out from under them. We don't have a lot of hours on this system so far, but our first four hours were great.