If you decide after listening to it that you do not like your new cd, you can remove it from the DOM Document using the removeChild method.

The removeChild method takes a single parameter: a reference to the soon-to-be-removed node.

Our new cd would therefore be removed in the following way:

$cdLibrary =& $cdCollection->documentElement; 
$cdLibrary->removeChild($cdLibrary->lastChild);

The removeChild method returns a reference to the removed node.