Or: Jump into FFM, add a control point where you want to seperate the leg. Then highlite that point and "create cross section". Then jump out into scene and "duplicte" leg, name one upper leg & rename other one lower leg. Then "jump-in" on each one (create new master), highlite the cross sections that don't belong with the name and "disconect from next cross section" in the options window. The advantage here is not having to rebuild parts in the MFM and you still retain the FreeForm model. Once you convert to the mesh model you can't go back. Try it on a simple cube first.