Which mechanism do you use to directly change an XML file from one DTD into another?

To directly change an XML file from one Document Type Definition (DTD) to another, you can use an XSLT (Extensible Stylesheet Language Transformations) stylesheet. XSLT allows you to define rules that specify how to transform the structure and content of an XML document to match the new DTD. By applying the XSLT transformation to the original XML, you can generate a compliant XML file that adheres to the new DTD. This method is efficient and maintains the integrity of the data while adapting the format.