If you've thoroughly read your
"Changing my foam nunchaku chain links!" thread you might have solved this problem a week ago.
If that still doesn't help, rctrue made a ball bearing swivel maintenance video a while back.
That should help give you a picture on how to disassemble a pair. For chain shortening, I used a bolt cutter to clip off the excess links.
EDIT
Having a second look at the video I found that Rich doesn't separate his chain from his swivels. It pretty much works the same way from when he removes the bearing caps from his sticks, but like I said from your other thread, have your swivel sit on an elevated surface from the rest of the setup.