My mother and my step father gave me my step dad's last name but now that I know and have a relationship with my Bio dad whom lives in Puerto Rico. I'm 34 years and live in Arizona. What can we do to get my last name changed legally? Does my mother and I need to go to Puerto Rico for a blood test? Thank you for any assistance.

You can get a name change through the Arizona courts and it is relatively simple. But if you also want your PR BC changed, that is more complicated. I don't even know if it can be done at your age. But it probably wouldn't help to physucally travel there. Call PR vital stats and inquire.