Inaccurate sex and gender narratives have saturated the political landscape, resulting in legal restrictions for people with queer genders. Biology educators can correct these false narratives by teaching scientifically accurate and queer gender and intersex inclusive sex and gender curriculum. Here, we interviewed four undergraduate biology instructors who were working to reform their sex and gender curriculum. Using their reformed curriculum to promote conversation in the interviews, we asked participants about their curriculum, their reform process, and the obstacles they faced in implementing their reformed curriculum. We noticed the instructors' journeys to reforming involved intense personal work and education, both at the beginning and iteratively throughout implementation. We found instructors focused on changing language and using a variety of inclusive activities in their undergraduate biology classroom, ranging from highlighting scientists with queer genders to assigning students to research the experiences of people with queer genders with adolescent hormone therapy. Instructors mentioned obstacles to implementing reformed curriculum, including fear of potentially isolating students and concern about the instructor's own positionality. Removing obstacles and supporting the process of unlearning exclusive ways of teaching sex and gender topics may bolster instructor efforts to provide more accurate and inclusive biology education.