My wife's QX50 has the same ring collar as the M37/56 for the shift boot. It's a very simple setup... you have the thin chrome ring/collar at the top of the boot, then a retaining groove on the inside that the boot is secured to with a simple ring clip, like a single wind of a spring,, that's IT!
The total height of this Chrome Collar Ring is 1/2 - 3/4" at the most.
So, to install on the Q50:
With the console removed and the boot inverted, so you're looking at the inside(stitched side) of the boot, completely remove the huge black two piece collar clip inside the boot.
Slip the chrome collar upside down from the inside of the boot, leaving 1/2 to 3/4' of the boot to allow enough slack for the spring clip to get a good grip on the boot.
Open the spring clip enough to clear the collar and boot and clip it to the retaining groove of the chrome collar piece.
Make sure the boot material is worked into the groove as much as possible to insure a secure fit with the spring ring clip and the collar retaining groove.
When you invert the boot back into position, the boot should be snuggly clipped into the collar groove with only the chrome collar ring showing!
So here's what the finished install looks like:
Before:
After:
Here's the part numbers for this:
349101MA1A 2012 M37 X Shift knob
34126EG000 (34126-EG000) Pin-Lock (Spring Clip Ring)
34929EG000 (34929-EG000) Cover-Control Lever (Chrome Collar Ring)