I just swapped out the trans axle in my S4 and it was a job but not too bad. I removed the calipers and hung them from the fender wells with hooks and didn't break the lines loose. Next I removed all the bolts holding rear suspension and torque tube, Lowered rear suspension and slid to the back and to the drivers side. I lowered and removed the transmission and tube as a unit with the help of three jacks and a prayer, Slid the unit out the back and changed everything over. I reversed to install and all went as well. I am slow and it took me about 20 hours to complete. There were no surprises except the speed sensor for the rear on the transmission and MR Merlin talked me through that - Thanks Stan! . I used air tools to remove most bolts as They were beast to get loose. I would recommend the help of a friend as the weight was a little more that expected and a concrete floor really helps. I kept a confused look on my face most of the time. My local transmission shop didn't want to do the job and then quoted 3k in labor to swap it out. I figure my labor is cheap and cost me around 200 shop time.
Now I know I can do such things with a little help.