ReplacePart Method
Replaces the contents of the specified part in the package.
Syntax
public void replacePart();
Remarks
If the part specified by the PartName property exists, the corresponding physical file will be replaced with the contents of the PartData property. The package file will be modified in place right away.
If the part doesn't exists, it's stored in interleaved format, or PartData is null or empty, an error will be raised.