Well I can figure that if you want to force it you could capture or knock out Vanguard characters and brainwash them as you have that crazy mad scientist brainwashed he could build a gender swap device. Then you could give them new names or keep their old ones but give them student ID's or teacher ID's.

For Tricking you could trick someone that they could use a gender swap mashine to infiltrate the friendship circles of the Angel's to spy on them.