First post here and not sure if people are still curious about this, but I did this on our just-purchased 2011 QX56.
It's a fairly simple process, took me about 30 minutes total.
1. Unscrew the four bolts located at the corners of the console box. The bolts are not standard phillips or flathead and require a "star" pattern bit (sorry, don't know the technical term for this).
2. Once the bolts are unscrewed, you can remove the console.
3. Next, you'll see the brackets that have to be removed. The two brackets run L-R (as opposed to front-back in relation to the car). The easiest way to do this is to separate the two pieces of carpeting in front of the 3rd row seats. It is affixed with velcro strips and you can see the seam where the two pieces come together if you don't have the 3rd row floor mat in place.
4. Lift the carpeting until you have the rear bracket exposed. Don't worry about pulling the carpeting out from the plastic trim, it will go back easily. Remove the bolts (and bracket) using either a standard hex bolt torque wrench or phillips head screwdriver.
5. You can now gain access to the front bracket by lifting further up on the carpet. Alternatively, lifting the carpet also improves access to the bolts through the carpet slots from above. Whatever works best for the tools you have on hand. Remove bolts/bracket.
6. Put carpeting back in place (be sure to tuck into the plastic trim along the sides).
7. You're good to go. There are 4 relatively large slits in the carpet where the bracket heads used to stick out. If this affects your aesthetic sensibilities, I've seen an OEM center mat that will cover this area:
http://infiniti.sewellparts.com/accessories-catalog/Accessories/QX-2011/5355.html
I hope this helps.
Chris