If you stick the jeep on a lift or prop the front end up, then shine a light up above the transfer case, then you should be able to see those bolts. Put the jeep in 4wd and in gear to hold the shaft in one place while you remove the bolts. Once one is removed spin the shaft and remove the other one and so on and so on.
I forget if I used a ratchet or a wrench but you need to reach above the transfer case and remove them. It's not very hard but you need to do it by feel. Your not gonna be able to look at what your doing without killing your neck.
It frustrated the hell out of me at first but it's way less of a hassle than removing the skid plate.
I'm not sure what your skid plate looks like but if you can touch the bolts with your hand you can get them out without removing it.