Anatomy - how the 1900s taille is put on

The hooks/buttons that are already closed are picked out in red
(in circles if visible, with arrows if invisible), the next step marked with green arrows.

Close hooks of the lining. Not all hooks are picked out here.
Hook middle flap to lining. Then pull collar round to the back...
...and close the three snaps there.
Button left flap onto middle flap, then the right flap onto the left...
...and finally hook closed the belt.