Given the scenario, it's clear that using Dr. John Kotter's 8-Step Model for Leading Change would be an excellent framework for your PowerPoint presentation. This model is particularly useful for ensuring that the significant organizational changes are implemented effectively and that managers are well-equipped to guide their teams through the transition. Here's how you might structure your presentation:

Slide 1: Introduction

• Title: Navigating Organizational Change
• Brief introduction to the context of the changes and the importance of effective leadership during this transformation.

Slide 2: Overview of Kotter's 8-Step Change Model

• Introduce Kotter's model as a proven framework for managing complex changes.
• Emphasize its relevance to the current organizational changes.

Slide 3: Step 1 - Do Urgency

• Explain the importance of building a sense of urgency around the need for change.
• Discuss strategies for communicating the importance and immediate need for the changes.

Slide 4: Step 2 - Form a Powerful Coalition

• Highlight the need to assemble a group with enough power to lead the change.
• Suggest ways to gather support from key stakeholders and leaders within the organization.

Slide 5: Step 3 - Do a Vision for Change

• Discuss how to develop a clear vision that will guide the change effort.
• Provide tips on how to effectively communicate this vision.

Slide 6: Step 4 - Communicate the Vision

• Emphasize the importance of frequent and effective communication.
• Offer methods for ensuring the vision is conveyed accurately and inspirationally across all levels of the organization.

Slide 7: Step 5 - Remove Obstacles

• Address potential resistance to change.
• Provide strategies for identifying and removing barriers to change.

Slide 8: Step 6 - Do Short-term Wins

• Stress the importance of visible, short-term "wins" to motivate and energize employees.
• Discuss how to identify and celebrate these wins.

Slide 9: Step 7 - Build on the Change

• Explain the need to analyze what went right and what needs improving after initial wins.
• Discuss how to sustain acceleration in the change process.

Slide 10: Step 8 - Anchor the Changes in Corporate Culture

• Highlight the importance of anchoring changes within the organizational culture to ensure long-term success.
• Provide strategies for making the change stick.

Slide 11: Implementing the Model

• Discuss practical steps for applying Kotter's model in the current organizational context.
• Emphasize the role of managers in each step of the process.

Slide 12: Conclusion

• Summarize key points.
• Encourage managers to embrace their roles as change leaders.
• Open the floor for questions or discussion to engage the audience further.

Slide 13: Q&A

• Allow time for managers to ask questions and discuss specific concerns about the change process.

This structure will help ensure that your presentation is clear, informative, and engaging, providing managers with the tools they need to lead their teams effectively through the organizational changes.