Im 15, How do I get my dad to stop being Racist?

Im black and my parents are from cape verde and Zanzibar in Africa. We came to America about 5 yrs ago but we have lived in Europe, Africa and now the U.S. My parents are both very arrogant and my dad tends to be extremely racist especially towards Hispanics of Mexican heritage. My mom is racist towards asians but shes not as verbal as my dads hatred for Mexicans. We live in TX so there are alot of Mexicans. My dad always makes racist remarks to mexicans and he always speaks about them in public but in our language. He hires Mexican landscapers and house maids to come to our house and doesnt raelly treat them with any respect. Hes never heard a problem with portuguese and spaniards when we were in Europe but he calls the mestizos "maspanos". Im suprised that they are even racist because they are both highly educated, they are well cultured, and on top of that they are black so they know how it feels to be discriminated because of skin colour.