At this point, realize that you have 2 props in the scene, the Prefitter and the clothing (LF2-LF1 Prefit prop and the leggings).  You will also copying morphs from one prop to the other.  Navigate to the taskbar, and select the 'Object' contextual menu, NOT the 'Figure' contextual menu.  Go down the menu to 'Copy Morphs From...'.

So far, we should be on the same page.