From a woman who shifted from being a stockbroker to a corporate psychologist via a break for a PhD:

…instead of honing your résumé, you craft a one-page autobiography that describes your skills and experience in the language of your chosen next field. When she first wrote her own bio, she noted that she worked with very successful people, that she had to understand what was driving them and that she helped groups of people reach agreement about their goals. She had needed all of those skills as a stockbroker, but they’d be just as valuable for a corporate psychologist.

Also recommended: speak – directly – to people who do the sort of stuff that you think you want to do.