Take a look here. Depending on which path you choose, it can be a daunting task. But, when you combine a little creative thinking with some strategic planning, making a change is much more doable.
Many people think of jobs in one-dimensional terms.
They define a job by its title, being a writer, a secretary, an accountant, a salesperson, etc. A marketing VP at an Internet start-up, for instance, has good interpersonal skills, is a strategic thinker and has experience creating marketing campaigns. She also is knowledgeable about the Internet industry as a whole. Which leads to the three ways to transition into a new career. An administrative assistant at an insurance company, for example, decides she wants to become a magazine writer.