Guided pathways reforms can take several years to implement at scale because they require a thoroughgoing redesign of a college's major functions, including: (1) organizing programs into career-focused meta-majors to enhance student recruitment and exploration and program improvement; (2) mapping clear paths to degrees, employment, and further education in collaboration with employers and universities; (3) structuring advising to help students choose, enter, and complete a program of study; (4) rethinking academic support to enable students to take and pass critical program courses in their first year of college; and (5) training faculty and staff to facilitate these reforms. Part 3 of this practitioner packet describes the process and timeline for implementing pathways and discusses how colleges can measure the effectiveness of their efforts. [For "Part 1: A Reform Moves from Theory to Practice," see ED582819. For "Part 2: Case Studies," see ED582821.]