Set in one's ways means that someone is very resistant to change and is very comfortable with the status quo. Antonyms for set in one's ways would include terms like adaptable, flexible, open-minded, and willing to change. Such a person enjoys experiencing new things, adjusting to new conditions, and embracing new ideas, and is always willing to take on new challenges. These people are creative, curious, and willing to approach problems from different angles in order to find solutions. They typically enjoy learning and growth, and are not afraid to admit when they may be wrong, which makes them a valuable asset to any team.