In the Administrator window for Server B, right-click the Directory Synchronization Requester object to display its properties.
Change the Server setting to Server B. When you do so, the following warning message appears:
"Changing the server in Responsible DXA can cause the loss of Directory Synchronization information. A full export of Directory Synchronization information will occur on the new Responsible DXA in the next scheduled cycle."
Choose OK to dismiss the warning, and then choose OK again.
Select the Requester tab, select Full Export, and then select Import on the Next Cycle.