The process by which managers develop technical or conceptual skills is not any different from the process followed by people in most of the profession to acquire the skills of their profession.
There are many different methods available for learning and developing new skills. Among others these include class room study, self study, by observing others, by apprenticeship, on the job training, and practical experience of performing different kind of jobs. In each of these alternated learning methods many different variations, tools and techniques exist. The exact nature of training and development process appropriate will depend on nature of subject, the nature of facilities available, and personal limitation of time and finances for the individual.
If a manager wishes to pursue a full time program of studies in management, he or she must have the financial resources and time for the same. Similarly, the ability of a person to learn as an apprentice will depend very much on the kind of guidance available from the person under whom apprenticeship is undertaken.