This guide grew out of material used in the Transformation Academy, a professional learning program for principals charged with achieving the rapid improvement of their school. The intent of that program is to help principals get started with transforming instruction -- the change that is at the heart of school improvement. Transforming instruction is a big job, engaging administrators and teachers over multiple years. Because the challenge can seem so daunting, school leaders can profit from some guidance in knowing where and how to begin. This guide provides that starting point. In the approach laid out in this guide, the principal starts down the road to instructional transformation by convening a select group of teachers as an action team (or A-team) that will look closely at how the principal makes time for instructional leadership and how teachers help each other improve their practice. The team, which includes the principal, will examine every aspect of the school's instructional system, a system that consists of planning, providing, adjusting, and enhancing instruction. The team considers learning obstacles their students might face and how well the school builds students' capabilities as learners. At key points, the team solicits input from the entire faculty. Using the information drawn from this initial examination, the A-team sets a course for achieving instructional transformation. Like the Transformation Academy from which it is drawn, this guide rests on the research and practice base of "Four Domains for Rapid School Improvement: A Systems Framework" (Center on School Turnaround, 2017). That framework identifies four areas of focus, and key practices in each, that have been shown to be critical for achieving rapid and significant school improvement, including instructional transformation, the focus of this guide. The Center on School Turnaround at WestEd presents this guide to assist both those participating in the Transformation Academy and the many principals who are charged with significantly improving their schools, but are unable to attend the academy.