Hello I will help you with your question,
The axle comes in one piece and you should not have to transfer parts from one to the other. Are you asking how to remove the axle from the transmission so you can install a new axle assembly?
See if the procedure below answers your question and if it does not help me understand what needs to be done so I can help you
You are saying that the stub shaft that is supposed to be in the transmission is now stuck in the axle assembly and you need to reinstall it in the transmission if I understand you correctly.
The procedure below is to remove it from the transmission so you can use a variation to remove it from the axle
let me know how I can help you with this
Photos always help but the stub shaft is supposed to be located in the transmission not the axle on that side, as you found out the axle is sold with a female splined hole to slide onto the shaft and the shaft is supposed to stay in the transmission when you remove the axle. The shaft has clips on both ends and the center portion where the seal rides so it is tough to find a spot to grab it without using the special tool shown in the procedure I posted without causing damage.
An alternative may be to remove the boot clamps from both axles and slide the tripod out of the shell and reuse the old shell on the new axle so you don't have to risk pulling the stub from the old axle.
Let me know how I can help and if you have pictures you can attach them with the paperclip tool in the toolbar above the posting window.
OK I will watch for your post
Yes that is as I described above and you will need a tool to safely grasp the shaft and slide hammer it out or release the band clamp on the boot and the whole tripod shell will slide off the axles and you can swap them shaft and all. That is what I would do so you don't take a chance damaging the stub shaft.
Let me know what I can do to help
You should replace the C clip that goes on the transmission end of the shaft. It is obvious that the clip on the tripod shell end is not going to be replaced and unless the one on the transmission end has been deformed it is not mandatory to replace.
We pull these axles and replace them for transmission service on a regular basis without replacing the clips and don't have problems with them so as long as the clip is not twisted or bent you can leave it. Just be sure it fits down in the groove and the ends meet squarely if you decide to leave it and if you install the new one do the same with it.
Let me know how I can help