I just finished playing Danganronpa 2, and was curious about fake Makoto's statements regarding the Remnants of Despair. Fake Makoto said that the Remnants of Depair attached some of Junko's body parts to their own bodies. One example I know of is that Nagito took Junko's hand. My question is this: what did the members other than Nagito take?
Fuyuhiko most likely took her eye (as seen in the picture where Ultimate Despair's despair-filled acts were depicted). We don't know who else took things, or what else was taken.
That's really all we know about the what. As for how - Mikan, obviously.
It's heavily implied that Mikan replaced her own womb with Junko's.