Make sure your dealer orders the correct kit. The kit for the 2500 is different than the 3500. Figured that out when I tried to get a 2500 kit to fit on my 3500. Dealer was decent about it and gave me a free oil change for my troubles.
If I remember correctly, the bracket closest to the cab (2500), bolts to the side of the frame, where as in my 3500, all 4 brackets set inside of a pocket on top of the frame.
The install took about 4 hrs in my 2014 3500, as I measured and remeasured several times before actually drilling. I like Me Again's use of a wire to check center before billing the large holes.