One of the first things I noticed needed doing whilst dropping the oil on mine, but I had it done at my local garage.
I will just mention if you are thinkin of doing it yourself, the mechanic (independant garage not Jeep dealership) said something about having to check the amount of torque needed when re-fitting the prop/UJ back to the diff which seemed important !
Dont think its much of a job tho, and I dare say further down the line when I'm used to the KJ more, I may well undertake jobs like this myself (I do know one end of a spanner from the other

).