木，你必须去应用程序\\ code \\核心\\法师\\销售\\等，并修改wsdl.xml和wsi.xml并添加或元素SKU你想按您的要求什么。

Muk, you have to go to app\code\core\Mage\Sales\etc and modify wsdl.xml and wsi.xml and add the element for sku or whatever you want as per your requirement.

<element name="sku" type="xsd:string" minOccurs="0" /> //in wsdl.xml
<xsd:element name="sku" type="xsd:string" minOccurs="0" /> //wsi.xml

如果你不想修改核心文件比你要覆盖它。

if you don't want to modify core file than you have to override it.