It finally worked for me once I understood what they were describing, The image in the manual is poor and misleading - just like the image pointing to the interior fuse box.
The access slot referenced is a slot underneath the power ports in the rear section of console. It is molded into the console as a little open top compartment. It is easier to feel to find rather than see if you are sitting in drivers seat. It is black so will not be obvious to see if in the garage. Once you insert the each fob, it takes a some seconds (more than one expects) to see the code display on the 48 inch display area where other messages appear (seat belts, etc). The delay was long enough that I initially thought it did not work and does not last that long.
I suspect you are not inserting the fobs in the slot.