It should be the same as far as bolting up but you will have problems with the sway bar and locker. There is basically a 4wd position switch but it will not work on the Atlas, Advance Adapters is working on something but I dont know if they have anything available now. On our X with an atlas, the position switch is not used so you can now turn the esp off at anytime so it must think it's in 4wd hi all the time. I would try to disconnect the swith and see if you can engage the lockers and disengage the sway bar and turn the esp off.
Those of you that think you know everything really annoy those of us that do!