It would be a diff swap, as the castings are different. I don't see how a simple switch could work as the actuator is a stepper motor controlling the 'amount' of lock. A stepper motor generally needs a controller of some sort- but that's where my knowledge ends. I guess it could be possible to use a switch. There have been successful rear locker swaps on other boards. The wiring is the hardest, but everything being on a common CANBUS makes it a bit easier. Once all the physical installation is done, then you need some of the ECUs programmed to match. This cannot be from the dealer, as their equipment can only program the equivalent of what was installed on the OEM build. You need a 3rd party flasher, like the Faultmate. If the linked D3 ARB locker is legit, that looks to be the easiest at this point as long as the presence of a true locker doesn't play nasty with the traction control system.