I wrote my book to help you do this for your own family members. This can be a source of income if you offer it as a service to other people. When you produce a great memoir it gives you great satisfaction and a unique legacy for the person whose memories it contains. There are people who already do this work but the field is wide-open. You don't need special writing or other skills. You can hire an experienced person to edit it. But a memoir gets much of its effect from being a record in the subject's own words, so you must get an experienced editor who has done similar work before. Your name will become better known as people read the memoir. The contact with family members will give you more interesting experiences and knowledge about human nature. This can lead to other writing assignments with memoirs or other projects. After you have your first memoir produced, you will be recognized as a writer who can handle important work.