system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do transsexuals change their genitalia? Does the new genitalia look and function normally?
gpt
As with most things, males seem to have it easier.  With MTF, most of the erectile tissue is removed from the penis and the skin is sutured back together, then pushed into the body to form a vagina.  A bit of the skin and nerve endings from the tip are relocated to form a clitoris, and the surgeon takes some bits of the scrotum and folds them up some to form labia.  The balls, as you may imagine, are removed.  If the surgeon is good, without quite a close inspection and excellent lighting, it is difficult to tell the difference between OEM and and aftermarket lady parts, and apparently, some even self-lubricate after a while.

I don't know as much about FTM, just that the replacement part does not function the same way the OEM one does.