The magician opens all of the doors of the dice boxes, top and bottom.
He shows the empty boxes to the audience, takes one dice from a small box and puts it into one of the dice boxes. The magician "magically" transfers the dice to the other box as the audience hears the sound of transferring. He can repeatedly transfer the dice from one box to the other one and at the end, the dice is shown to have disappeared from these two boxes and it is come back to the small box from where it started.
Click "HERE" to watch video.