What is a good technique to master an accent?

I have my drama acting essment scheduled for the end of the month and I am playing Reverend John Hale as part of Arthur Miller's The Crucible, and would really like to be able to pull of Machusetts accent. Does anyone have any helpful techniques or exercises that I can use to better myself? I'm Scottish and the accent does work with the role, but I would like to be able to show how competent I am as an actor. Thanks x