Boyfriend's Mom needs a solid health transformation. What do we need to do to ensure she is on track after release from the hospital?

My boyfriend's mom just had heart attack today and hospitalized. Last time she had it was 2012. She discontinued her heart medication. She said it made her uncomfortable. She didn't follow up the heart med she might need for the past few years. Also a series of life events cause life stress, unhealthy diet, lack of exercise, eventually cause her current heart attack. What do we need to do to ensure she is on the track on her health after release from the hospital? She is living with her relative and we don't always see her. She is stubborn to change until she really have to. she is picky with food, don't eat enough vegetables and don't like drink water, she drink diet coke. Her overweigh situation had cause her difficulty to walk. Also arm injured easily. It's a long time problem. How to reduce her weight and encourge her make right choice. Her job require her to be physically healthy. She can't lose job because she need money to live. And there are other problem envolved around her. She need health and wealth. Neither of them exist yet. She is at retirement age but can't retire. She is living with someone let her stay. It breaks my heart to see my boyfriend's Mom go through these when it's all preventable. How to be the best help without causing frustration. Because asking her to eat right, exercise might be difficult yet possible. We want her good for a long run!