Deve estar no seu DVD / ISO. Exemplo de localização do EX 2010:
x:\Setup\ServerRoles\ClientAccess\sync\xsd\v2.0
Directory of x:\Setup\ServerRoles\ClientAccess\sync\xsd\v2.0
09/25/2009 01:14 PM <DIR> .
09/25/2009 01:14 PM <DIR> ..
07/21/2009 08:27 PM 1,043 foldercreate-request.xsd
07/21/2009 08:27 PM 751 folderdelete-request.xsd
07/21/2009 08:27 PM 550 foldersync-request.xsd
07/21/2009 08:27 PM 1,189 folderupdate-request.xsd
07/21/2009 08:27 PM 1,166 getitemestimate-request.xsd
07/21/2009 08:27 PM 1,299 meetingresponse-request.xsd
07/21/2009 08:27 PM 1,261 moveitems-request.xsd
07/21/2009 08:27 PM 1,242 provision-request.xsd
07/21/2009 08:27 PM 2,003 search-request.xsd
07/21/2009 08:27 PM 8,358 sync-calendar-request.xsd
07/21/2009 08:27 PM 7,119 sync-contacts-request.xsd
07/21/2009 08:27 PM 261 sync-email-request.xsd
07/21/2009 08:27 PM 16,028 sync-request.xsd