[b_nosoff]

static void Job001(Args _args)
{
    XmlDocument xmlDoc = new XmlDocument();
    XmlNode     rootNode;
    XmlNodeList elementNodes;
    XmlNode     elementNode;
    int         elementNodesLength;
    int         i;
    ;
    
    xmlDoc.load("C:\\Users\\user\\Desktop\\Document.xml");
    
    rootNode = xmlDoc.documentElement();

    elementNodes = rootNode.selectNodes('descendant-or-self::text/text2');

    elementNodesLength = elementNodes.length();
    
    for (i = 0; i < elementNodesLength; i++)
    {
        elementNode = elementNodes.item(i);
        
        elementNode.attributes().getNamedItem('atribut').value('new value');
    }
    
    xmlDoc.save("C:\\Users\\user\\Desktop\\New document.xml");
}

Дальше сами разберетесь?