You can use the Copy Geometry tool to replace the geometry of an existing datum with the geometry from a different layer. To do so:

1. Select the datum whose geometry you want to replace.
2. Click the Copy Geometry button .
3. Alternatively, click Show Attributes and then, from the Datum Attributes dialog, click the Actions menu and select Copy Geometry.

   

4. You are prompted to Select Element to Copy Geometry. Drag a rectangle around the element whose geometry you want to copy. You can minimize the Datum Attributes dialog if it is obscuring the element you want to select.
5. The Copy Geometry dialog opens. If you selected more than one element in the previous step you can choose the correct one from the list displayed here. After selecting the element click Next.

   

6. The next step of the Copy Geometry dialog is displayed. In this step you can choose whether to move the start and end nodes of the datum. When you have selected your desired settings click Copy.
   Note: Moving the nodes may break network topology.