Well the best way to go about it is probably to just tell him why u want to leave. Kinda like u just told us. being strait forward and honest is your best bet. He cant stop u from doing so at your age.
Make sure to plan for your move well. Get in to college or work of some sort as soon as possible and basically just live responsibly. Once u do that your father will back off. It also helps to have family in the area u plan to move to of course.
U do have to remember to look at is from his side as well. 19 is still young. In many ways i was responsible at that age but at the same time had a very far way to go in other areas but dint see it at the time.
good luck yo
