Final answer:
Stevenson convinced Johnny D (Walter McMillian) to accept his legal guidance by demonstrating his knowledge, expertise, and commitment to the case.
Step-by-step explanation:
Stevenson convinced Johnny D (Walter McMillian) to accept his legal guidance as his attorney by demonstrating his knowledge, expertise, and commitment to the case. He likely presented evidence to show that he had experience and success in similar cases, and he may have explained the legal processes and strategies he planned to use. Stevenson may have also built a rapport with Johnny D by showing empathy, understanding the importance of the case, and assuring him that he would do everything possible to fight for his rights and prove his innocence.