Change is the most integral part of all living beings, and is also the most difficult part too. Why is it so difficult? I guess there are two parts in this answer-
1) We are afraid of change.
2) We are upset with the change.
So, what is difference between being afraid and being upset? We are afraid because we are not confident of our ability to face the change. There is something within us which doubts our capability to face the unknown and succeed. Our past failures or other failure stories contributes to this. This thing is very internal, you can overcome this by preparing yourself in a better way for the change.
Being upset is something external, there are some elements outside your control that make you upset. You being not involved in the decision of change, some hidden things can contribute to make you upset.
After knowing this, as a leader how do you prepare your team for a change. As a leader you should be as transplant as possible with your team, don't keep any hidden agenda from your team, show your team what exactly is expected from them and what they can expect when the change occurs. Showing a realistic picture is very important, you should not frighten the team by showing pessimistic view neither should you be too optimistic and promise them what is not expected to happen. Being realistic is very important because it can help the team prepare for a change in better way, thus taking care of their fear of change. Also it doesn't left anything away from the team thus getting them involved in the change and removing that uncertainty and hence the upset feelings.
So, be open, and enjoy the change with your team and prepare for bright future!