I had a disconnect D30 and it didn't have a C-clip. I don't know why yours would???
If it does indeed have a C-clip, then when you pull the center pin, you just push on the spiders and they fall out. However.....from previous experience with D30s, and from your pic (if that is from your vehicle) you won't be getting the cross shaft out without removing the ring gear! It would be pretty tricky to remove the ring gear without the carrier being out of the vehicle, although I guess it could be done. Take a good look at the cross shaft, and see if it has some flat edges facing you. It may be such that you just need to rotate the cross shaft 90 degrees so that you can then push the innner axle shaft in a tiny bit and expose this alleged C-clip.
However, since you can't remove the cross shaft with the ring gear on there, I don't see how they would have put a C-clip in there to begin with!!