There is a video around showing the whole process but it keeps moving (disappearing) so I can't give a link.
He builds a large structure and then sculpts full size in modeling clay after having done a number of smaller version exploring the idea.
He builds an outer structure around the sculpture
He then makes mold pieces off the clay of silicone with fiberglass backing and installs brackets that will secure the pieces to the outer structure and pulls the pieces, in some cases destroying the clay sculpture.
He then experiments repeatedly to get the right colors for skin tones and textures - like pores on the fanny and belly of the huge pregnant woman.
He then assembles sections of the mold into larger areas and applies the colored gel coat to the inside of the mold and lays the fiberglass mat or cloth onto that. Some portions of the figure are done in soft silicone so that he can insert hair on top of head, face, arm pits and pubis.
The largish subsections are then assembled into the full sculpture or major parts if it is so big it has to be moved in sections.
This one http://www.youtube.com/watch?v=pTy5cORM3CI
which is part 2 and
this http://www.youtube.com/watch?v=Nh3SBzY658w&NR=1 is part 3