What you do is take a ball point pen apart, find the tan section that tapers, pull the point off that, and yank the ink tube out of the other side.
Then, you saw the clear plastic point of the pen off, twist a piece of 1/16 armature wire into where the ball would normally be, and then push the clear part back on over the tan part, which is now the wrist. The wire will stay in, but you can epoxy or tape it if you like.
The result is very expressive hands (due to be the ability to remove them). I know what you're thinking: "but Don, why not just use square brass tubing? Well, when doing it that way, to turn the wrist you have to twist the wire and each time you change the position of the hand you are wearing the wires out more. This design allows you to turn the hand at the wrist, which contains no wire. As a result, the arm wires are going to last longer no matter what the hands are "saying".
One caution: this process is very messy because of the ink. You want to wash it out really well so it doesn't get all over your puppet. But it works great.
Here is some animation:
(Head replacement test)
(First three shots)
There is no sound effect for the second shot, and the animatic is seen briefly, but it's not "set in stone" and is subject to change