Educating and dealing with Homophobic Parents

I am still questioning my gender but I've done a lot of researching and I'm pretty sure I'm transgender but I was wondering if I do decide to transition I'd like to know how to open my parents eyes to be accepting towards whatever I decide. You can't change people's opinion's and I realize that but I am very worried and care a lot about what my parents and family think I at least want to provide them with knowledge and try to get them to support me. How do you deal with parents having negative thoughts about being transgender?