If your talking about the succubus teacher that can jump you in transylvania. Go to randy in succubus tower and ask her to teach you some magic she'll ether teach you right away or say you need study more (there's a place in succubus tower for that just look around, the stats called mystic) and the first spell she should teach you is how to grow dicks and such. after that its straight forward encounter the teach. beat her up or make her HORNY. and there should be option to make her grow a dick. Enjoy getting pegged.