Edit profiles or paths from which forms are created.

In some cases, such as in sweeps or swept blend, this may be easier in x-ray mode.
 Mode panel
Mode panel
 (Edit Profile).
 (Edit Profile). 
  The drawing area will enter sketch mode. However, forms made from reference geometry will not have a sketch mode and will require direct modification to the reference geometry.
 (Finish Edit Mode).
 (Finish Edit Mode).