The words “meaningful engagement” have turned up several times at different places on this site. There is perhaps no better single answer to the question, "What are the key leadership actions I must take during this phase?" Elsewhere you read, “change imposed is change opposed.” It is a profound statement and quite the opposite of another that wisely says, “people support what they help to create.” Both are aspects of the same very powerful dynamic. Part of the human condition for a great many when it comes to change is the yearning for contribution and a sense of ownership of the change being made. Contribution and a sense of ownership are the essence of meaningful engagement.
Meaningful engagement, like change in general, does not happen by accident. It is the result of thoughtful planning and it is the point at which executing the project plan and change management become one. It is helpful to think of engagement as a cycle of events not unlike the Plan-Do-Check-Act cycle from quality improvement. Like PDCA, engagement has a process quality to it and consists of four steps.

- Engage - enlist the direct participation of the right mix of people in some issue of relevance to the change
- Co-create - charge the team with the work necessary to develop recommended solutions to the issue
- Execute - the team socializes, enlists further engagement to implement, and monitors the solutions
- Adjust - the team and members of the change impacted area collect and analyze data related to the solution's performance and iterate the process as needed
The Engagement Cycle is elaborated in a link below. It is one of the most important tools on the site.
The art of managing change is to integrate fully the Engagement Cycle with project steps to maximize effectiveness. The ways of engaging people in change are limited only by a leader or manager’s imagination. Any activity that makes a meaningful contribution to the change step at hand and deepens understanding and commitment should be considered.