Telling the right story is the first step.
I don't know about you, but the moment I lost interest in mathematics was the day in 9th grade when, struggling with an algebraic formula, I asked the teacher what it meant and what it was for, and her answer was a curt and dismissive: "Because it's on the test."
That didn't help me understand how x2 + 3y = 72 was relevant to my life. As far as I was concerned, it was just a bunch of random numbers. And in 9th grade, my first year of high school, "it's on the test" didn't help me do anything but panic. Needless to say, my grade reflected that.
My friend's physics teacher had a better approach: By telling stories about sailing ships headed for cliffs ("calculate the angle") or balloons taking off from earth ("calculate the velocity"), she was able to put the numbers and formulas into context and make much more sense of it all. The teacher didn't claim that she'd need this information for some nebulous event in the future, either; he pointed out ways it could be useful to understand events in her daily life.
The same thinking applies to change management: When you tell employees that they have to make a change, but your explanation never gets beyond a vague "because it's good for the business" and you don't help them see how it will be relevant or useful to them, you end up with a lot of confused, reluctant and possibly downright mutinous employees.
I've talked to senior leaders who insist that the average employee doesn't understand and doesn't need the details about the big picture; that it's pointless to try to explain it to them because they're not interested in anything outside of their own little job. Sure, there are some employees like that. But in a successful, growing organization, there are far more people who want to be engaged in the full picture, who want to know how they fit into that picture, and who really want to know what it takes to be successful within it. These people are prepared to make changes - as long as they feel like they're making those changes as part of the team, not because they're peons who're forced to do The Boss' bidding.
So how do you get them engaged? It starts with telling the right story
If you're making changes because you have research that says the next 5 years will bring revolutionary change to you industry and you need to make sure you're ready, tell that story. Show people the research, walk them through your thinking, demonstrate how the changes you're making now will ensure business success in the short, medium and long-term. Tell them how it's going to become part of your culture, your brand story, your sales strategy - and how it's going to give them more opportunities to shine.
If you're making changes because the business is in trouble, it's even more important to tell the right story. Your employees already know there's something wrong; making unexplained changes will only increase the feelings of panic. Instead, create a story that recognizes the current challenges and explains how the changes are designed to transform the business. It's okay to acknowledge that some of the changes will be difficult for some people, as long as you're honest and logical in your narrative.
People don't get engaged in facts; they get engaged in stories. When you create a narrative for your changes, you'll find your people are more willing to become part of the team rather than a roadblock to the process and the company's ultimate success.