Открываем файл index.main.php или _sidebar.inc.php и вставляем туда PHP

Пример:

// PHP script goes here
include '/path/to/your/script/file.php';

// ------------------------- "Sidebar" CONTAINER EMBEDDED HERE --------------------------
// Display container contents:
skin_container( NT_('Sidebar'), array(
	  // The following (optional) params will be used as defaults for widgets included in this container:
	  // This will enclose each widget in a block:
	  'block_start' => '<li class="$wi_class$">',
	  'block_end' => '</li>',
	  // This will enclose the title of each widget:
	  'block_title_start' => '<h2>',
	  'block_title_end' => '</h2>',
	  // If a widget displays a list, this will enclose that list:
	  'list_start' => '<ul>',
	  'list_end' => '</ul>',
	  // This will enclose each item in a list:
	  'item_start' => '<li>',
	  'item_end' => '</li>',
	  // This will enclose sub-lists in a list:
	  'group_start' => '<ul>',
	  'group_end' => '</ul>',
	  // This will enclose (foot)notes:
	  'notes_start' => '<div class="notes">',
	  'notes_end' => '</div>',
  ) );