Select XML Schemas for Comparison
XML Schemas can be selected for comparison in various ways. You can open the XML Schemas in a new XML Schema Comparison window, open an XML Schema comparison document (*.xsdif) from the file system, or change the XML Schemas in the currently open XML Schema Comparison window. XML Schemas that have already been compared before are available in a drop-down list in the title bar of each component. Note that you can select only one schema per component.
To select XML Schemas in the active XML Schema Comparison window:
1.In the left component of an existing XML Schema Comparison window, do one of the following:
•Click the Browse 
icon and select a file in the Windows Open dialog box.
•Double-click the title bar, enter the path to a file and press Enter.
•Click the 
button and select a previously compared XML Schema from the drop-down list.
2.Repeat step 1 for the right component.
To open an XML Schema comparison document:
•Select the menu option File | Open Comparison File... and choose an *.xsdif file from the file system. The comparison is opened in a new XML Schema Comparison window with the name of the comparison document appearing in the comparison window tab.