Accent Reduction in English: American English

Next month I will begin to teach an American English conversation course in a hospital in Indianapolis. This class is part of a program called American English for Internationals, which is designed to help international physicians, medical researchers, and other healthcare professionals to modify their accents in English to speak more like Americans. This will help them communicate more effectively with their colleagues and patients, and in social situations with neighbors and other Americans they associate with. Modifying your accent in a foreign language as an adult is not easy, but it can be done with practice and patience. Language habits, as with all habits, can be hard to change, but it's worth the effort. Your thoughts?