Submit work that qualifies as "memoir." Memoir tells the story of significant events in a person's life. The writer must have a clear vision of how those events changed or shaped his life.
Read a variety of memoirs. Learn about what works and what doesn't. Analyze several memoirs and note how each is structured and what sets it apart from other genres, specifically biography and narrative non-fiction
Participate in writing workshops to hone your skills. Look for programs focused on memoir and personal essay. Many memoirs have grown out a single personal essay.
Attend writing conference where agents will be present. For an additional fee, many conferences offer the opportunity for a one-on-one with an agent. Before the meeting, make certain that your pages are ready.
Set aside any concerns about legal issues such as libel. Write what you feel needs to be written. An agent may offer some advice once she opts to pick up your book, but a publisher will have the work vetted for any potential problems.
Be prepared to promote your book. An agent is more likely to take on a book if you have a platform and a marketing plan that uses your expertise, professional connections or position in the community. Use your personal spotlight about you and the book.