Are you responsible for implementing a change that you don't understand or even agree with? That's a tough situation but consider this...
"It's like driving at night in the fog. You can only see as far as your headlights, but you can make the whole trip that way" - E.L. Doctorow
A good first step is to ask the people above you to help you understand the reason for the change.
Failing that...
Set some short-term milestones and create some small wins. A little success can keep you and your team on track until the bigger picture becomes clear.
People are looking for a sign that they are making progress.