I assume you are asking about the pin that goes through the end of the big cross-shaft to hold it in the carrier.
The pin, that goes through the end of the cross-shaft, is accessed by removing an allen wrench headed bolt in the side of the carrier. It is a female threaded pin, probably 1/2" - 3/4" in. There is a special, threaded on one end, "L" shaped wrench that came with the ARB to remove this pin. If you don't have this, it is harder, but not impossible to remove the pin. When I was working on my ARB, I couldn't find the special wrench, so I just kept trying to thread in some various small bolts I had lying around into the pin. Eventually I found one the correct size and with the correct thread and was able to remove the pin. You may have to tap the big cross-shaft back and forth a little to get the little pin out, as they tend to bind up a little if they haven't been removed for a while. I had to use a pair of side cutters (dykes) on the small bolt, to work the pin out (same process I use to remove cotter pins). Squeeze them down on the bolt, close to the carrier, then pry them against the side of the carrier to work the bolt/pin out. Of course, don't squeeze them too hard or you will cut the bolt off and really be screwed!! Once this pin is removed the cross-shaft should just tap out, without too much effort.
Once I got the pin out, I wire brushed it off and put some anti-sieze on it before I reinstalled it. I don't know if the anti-sieze will stay in there or eventually get washed out by the diff. oil but I thought it was worth a shot.
HTH.
