Over the last eight years, the University of Virginia Partnership for Leaders in Education (UVA/PLE) has partnered with over 50 districts and state education agencies across the country to embark on high-level change at the state, district, and school levels through the use of leader competencies. This guide calls upon practice-based experience, expertise, and insight to provide both technical assistance and thought leadership to districts and systems involved in "school turnaround." Specifically, the authors discuss the behavioral event interview (BEI) and turnaround leader competencies, and explain how each of these can support the turnaround endeavor. A BEI is a particular type of interview that allows candidates' suitability for a position to emerge by measuring their competencies, which are ways of behaving, acting, and feeling that support a person's performance in a particular role. This guide provides a rationale for using BEIs and competencies, and it takes an in-depth look at how they might be used in practice. It also explores how several districts and states use these research-based processes to improve selection as well as other human resource functions, such as school assignment and professional development. Redesigning for a Competency-Based Approach: SEA Support of LEA Principal Selection is appended.