using( var document = DocX.Load( "Report.docx" ) )
    {
      foreach( var p in document.Paragraphs )
      {
        // Gets the paragraph's charts.
        var charts = p.Charts;
        if( charts.Count > 0 )
        {
          // Gets the first chart's first serie's values (in Y).
          var numbers = charts[ 0 ].Series[ 0 ].Values;
          // Modify the third value from 2 to 6.
          numbers[ 2 ] = "6";
          // Add a new value.
          numbers.Add( "3" );
          // Update the first chart's first serie's values with the new one.
          charts[ 0 ].Series[ 0 ].Values = numbers;
          // Gets the first chart's first serie's categories (in X).
          var categories = charts[ 0 ].Series[ 0 ].Categories;
          // Modify the second category from Canada to Russia.
          categories[ 1 ] = "Russia";
          // Add a new category.
          categories.Add( "Italia" );
          // Update the first chart's first serie's categories with the new one.
          charts[ 0 ].Series[ 0 ].Categories = categories;
          // Modify first chart's first serie's color from Blue to Gold.
          charts[ 0 ].Series[ 0 ].Color = Color.Gold;
          // Remove the legend.
          charts[ 0 ].RemoveLegend();
            
          // Save the changes in the first chart.
          charts[ 0 ].Save();
        }
      }
      // Save the document.
      document.SaveAs( "ModifyChartData.docx" );