Why would you ask this question at all, you haven't even done any research as to what you even plan to accomplish.
What gears did they come with....,wow.
If you want someone to tell you how to do it and do all the researching for you come out and say it, I dunno what else to say really. I am of the belief you research all of what you can, and then you ask for help where you get stuck. Researching it will also provide you with a better knowledge of what you need to get as to accomplish your task at hand, whether or not you'd be able to do it yourself, and how much other alternatives would cost.
So it goes.
The differentials themselves probably will be able to be interchanged, but that means grabbing the pinion if it is a different gear ratio(I"m assuming you want to go lower). And then you have to have the preloads setup(not like new bearings being setup though). Then you have to have it shimmed right etc... or you could pay for installation of it. If this donor wrangler has a dana 35 rear, why would you bother putting money into something that is worthless if you are having to regear then you obviously are running a bigger tire than what the 35 can handle.
my two cents.