Resistance to change is a natural reaction - and once managers realise that, it makes managing it that bit easier.

If you look at John Fisher's Change Curve, you will see that people (and groups) react to change in stages, from disbelief all the way to acceptance.

Description: http://www.practical-management-skills.com/change-management-theories.html.

Diagram: http://www.practical-management-skills.com/support-files/process-of-transition.pdf

They will move along this curve at different speeds, and may get stuck along the way.
As a change manager, your job is to recognise where people are on the curve with regards to the change issue, and aim to stay one step ahead.

If they are still feeling angry, it is important to listen to them, rather than force them to move forward.

When they start asking about what the new change will look like, then is the time to talk about the change and the benefits that can be gained.

Communication is essential; ideally face to face so that misunderstandings can be avoided.

As a manager, you need to be patient, empathetic and confident in the way forward if you want to bring others with you.

Hope that helps!

We do have a workbook on the subject that goes into more detail:
"http://www.practical-management-skills.com/how-to-manage-change.html