Clear XML Data and remove movie clip

I have 2 quick (I hope) questions.

Is there a method to delete or reset the xml data to nothing after using… myXML.load(myfile.xml") ?

My xml file name is dynamic and I want to clear the old children and node values and create new ones based on a new XML file.

And what is the best method to remove a movie created by createEmptyMovieClip?

Cheers in advance!