How To Create New XML DOC With Properties From Existing One

I have an XML doc that looks like this:

Java Code:

<?xml version="1.0" encoding="UTF-8"?>
<model>
<id>_1</id>
<nodes>
<id>_2</id>
<stencil>TASK</stencil>
</nodes>
<nodes>
<id>_3</id>
<stencil>TASK</stencil>
</nodes>
</model> mh_sh_highlight_all('java');

I have to create another xml doc with the properties of nodes from the first doc. For the new doc I have to create a parent node called "definitions". Instead of the "model" node in the first doc I have to create a "process" node in the new doc that has an attribute "id" which value is the same as the content of the "id" child node of model. For each "nodes" node in the first doc if their "stencil" child node content equals "TASK" I create a "task" node in the new xml doc.

Java Code: <?xml version="1.0" encoding="UTF-8"?>
<definitions>
<process id="_1">
<task id="_2">
</task>
<task id="_3">
</task>
</process>
</definitions> mh_sh_highlight_all('java');

[code]....

I just wanted to know if this is the correct way to define the respective classes.any way to create and fill the nodes for the new doc using this classes? I am used with DOM parser and I know how to create nodes and fill attribute values, but I have always done this job in a single class, not using different classes for the elements.