You will stop producing testosterone (so say bye-bye to massive muscle growth), your penis will go in and turn into a vagina, and you are now a female (girl) with just an X chromosome.

Discuss this monstrosity. Now with all that said, imagine for those that decide to get a sex change.

FYI, every single one of you was a girl when you were a fetus. However the Y chromosome had genes that caused that vagina to come out and turn into a penis. If no Y chromosome is present you're a female with a vagina.