Managers usually are more skilled in the technical requirements of change, whereas leaders have a better understanding of the attitudinal and motivational demands that the followers need. Note the difference: In the beginning, the skills of a leader are essential. No change will ever occur if the psychological needs are unmet. Once change has begun, the skills of a manager are needed to maintain needed change.
A good exercise when you face change is to make a list of the logical advantages and disadvantages that should result from the change, and then make another list indicating the psychological impact. Just seeing this on a sheet of paper can be clarifying.