The SaveWebPart element updates an existing Web Part in a page. This element is defined as follows:

 <s:element name="SaveWebPart" xmlns:s="http://www.w3.org/2001/XMLSchema">
          <s:element name="pageUrl" type="s:string" minOccurs="1" maxOccurs="1"/>
          <s:element name="storageKey" type="s1:guid" minOccurs="1" maxOccurs="1"/>
          <s:element name="webPartXml" type="s:string" minOccurs="1" maxOccurs="1"/>
          <s:element name="storage" type="tns:Storage" minOccurs="0" maxOccurs="1"/>

pageUrl: The location of the page. MUST be formatted as either an absolute URL, a server-relative URL, or a site-relative URL. The location specified MUST be in the current site (2) or any child site (2) of the current site (2) that is also in the current site collection.

storageKey: A GUID that specifies which Web Part to update. This MUST correspond to a Web Part that is specified in one of the Web Part zones in the view specified by the storage parameter. The Web Part MUST also be serializable in one of the formats supported by this operation.

webPartXml: An XML-encoded string containing the contents of the Web Part being saved. After decoding, this MUST be in a format<109> supported by the server.

storage: Specifies whether to save the Web Part referred to by the storageKey property to the public view or the current user’s personal view of the page. If not set, the server MUST interpret it as "Personal".