I have never actually tamed a button, or even seen a tame button. Some of mine will eat bugs from my hands and they aren't too nervous around me, that's how far I've gone personally. But I have seen pictures and read stories about tame buttons, so I know it can be done. My guess is that the way to go with chicks, is heat. Take them out of the brooder, make sure your hands are warm, and make them associate your hands with heat - put them in your lap with your hands over them while watching a movie, or something like that. Try to make them follow your hand and go under it themselves if you move it a little away(I've done that with a newly hatched chick, but I don't know how old they can be for that to work). Talk to them, feed them small bugs. I don't know if it will work, but you can always give it a try.