He decided to keep it fairly simple. He'd just switch his sex from male to female, and see what it was like. If he wanted to have a different body he could always change it later. He changed the gender setting on the Chronivac and it adjusted his other measurements slightly.
14/female/5'3"/105
He pressed Change and waited for it to take effect. Soon he started feeling warm and tingly all over. His body was suddenly producing a rush of female hormones, making him become super aroused, and it was only becoming stronger, slowly beginning to replace his male hormones altogether. And as they did so, his body began to change.
He started panting as he felt a weird tenseness in his chest, pulling off his T shirt to see his nipples perking up. He touched one and almost moaned as he did so- lured in by the pleasure, he started playing with the other too, and as he eagerly fondled himself, his body started forming breasts. Transfixed by them, he barely noticed as he lost several pounds and two inches, only caring about continuing to feel good from his sensitive chest.
Suddenly a twinge in his crotch distracted him from his newly formed mammaries, although when he looked at himself in his mirror he realized he loved the way he looked with boobs. He dropped his pants and felt at his scrotum, where he felt the twinge, but suddenly felt the balls move up inside him, beginning to become ovaries. Panting as the loose skin started inverting and reshaping into feminine lips, his attention turned to his cock, but to his surprise, a single rub of it made him feel an intense jolt, and after he took his hand off it it began to retract, pulsing intensely but slowly shrinking, losing inches and definition until it was a barely visible nub above his newly formed slit.
Finally, she panted as the vaginal opening formed just inside her slit, her reproductive parts fully forming and connecting to the feminine passage. And when it stopped, she looked up at herself in the mirror, surprised by how similar she looked to her male self. She really did look like himself, but a girl. But she knew she'd need a different name to Trevor now. Maybe... Tara? Yeah, that sounded good for now.