The German Anatomy Book
— Frank Cristiani —
Corvin had worked at the Görlitz morgue for years. Most people would find the job grim, but for him it was perfect.
Buried deep in old internet forums and half-translated texts, he had discovered a forgotten technique, a way to detach and reattach limbs, organs, and even entire body parts without pain, without blood, and without any medical tools.
Just precise pressure at certain points along the joints and connective tissue.
He had practiced for months on the cold bodies that came through the morgue.
Feet, hands, eyes, even full reproductive systems came off cleanly and could be reattached perfectly between the assortment of cold bodies at his disposal. But he had never tried it on a living body… until tonight.
A young woman named Emilia Krause was brought in after a sudden brain seizure. She was beautiful, mid-twenties, long dark curly hair, soft feminine features, and a body that was still warm. Corvin stared at her for a long time.
He started with her left leg.
A few careful presses at the hip joint and the leg detached without a single drop of blood. He did the same to his own leg. No pain. No resistance. His leg came off cleanly. He pressed her leg against his stump, he could feel as the muscles, nerves, every single tissue connected to his new limb, the skin sealed itself with a strip of color that transitioned within her leg skin tone and his. He could move it. Feel it. It was his now.
He did the same with the other leg, then both arms. Her hands were smaller, softer, with manicured (though slightly chipped) nails. They responded perfectly to his commands.
Next came her breasts.
He pinched the precise points around each one and they came free. He removed his own flat chest and pressed hers into place. The moment they attached, color returned to the pale flesh. Her pink areolas darkened slightly and came alive. When he brushed his new nipples with her fingertips, a sharp, electric pleasure shot straight between his legs. His cock began to harden.
He walked to the bathroom mirror.
There they were, her perfect, full breasts now sitting on his broader male frame. They looked comically out of place within his large chest on him, but they were sensitive, warm, and undeniably his.
He returned to the table and kept going.
One by one he replaced nearly every part of himself with hers: waist, hips, torso, butt... until only her head remained on the table. Then, piece by piece, he disassembled her head as well, replacing his own hair, eyes, jaw, tongue, ears... with hers. His original body parts had been carefully reassembled onto the body on the table as he traded them.
When he finally stood in front of the mirror again, the transformation was complete.
He was shorter now. The weight of her breasts and the sway of her wider hips threw off his balance at first. Long dark curly hair framed a delicate, beautiful female face. Emilia’s face stared back at him, fully alive, flushed, and breathing.
Corvin, now in Emilia’s body, ran her hands slowly over the soft curves. He cupped the breasts that were now his, feeling their weight and sensitivity. One hand drifted lower, between the smooth thighs, and found the warm, wet folds of her pussy.
A soft, feminine moan escaped his new lips.
He had read that he had roughly 72 hours before necrosis would begin to set in. More than enough time.
He smiled at the beautiful woman in the mirror.
No more testing with cold dead bodies, it was time to explore.

Hey guys! Ever since I found out about the stories of the "SCP Foundation" I had a feeling some of them would be a good fit for the stories I write, and after some research found about the SCP-3484, a book that has instructions about how to detach and re-attach body parts. As far as I know the author is WrongJohnSilver and you can find the file for SCP-3484 at https://scp-wiki.wikidot.com/scp-3484
Let me know what you think!