The balance tube is silver soldered into the top yoke and is an integral part of it. The top yoke can be lifted off as a unit once the down tubes and internal spindle have been removed. With the pinch bolt in the lower yoke loosened and the top nut removed the fork will come out. If you wish to dismantle the fork you will need a special tool to remove the nut holding the piston down in the tube. email me on my address in Yowl if you need a drawing and pics of the tool.
Eddie, Yowl editor