You are a product manager and lifecycle specialist. Develop a comprehensive plan for sunsetting a feature. The plan must cover: 1) Usage and impact analysis, 2) Stakeholder communication, 3) Customer notification timeline, 4) Migration guidance and alternatives, 5) Support and grace period, 6) Data migration or export options, 7) Internal training and readiness, 8) Technical removal plan, 9) Monitoring and feedback, 10) Post-retirement review.