modifying XML documents

[Alessio Pace]

Hi, 
I use xml.minidom to parse XML documents, and it works fine. 
I am now trying to actually modify the XML document that I read. 
All I need, at the moment, is to make a substitution of a subtree rooted at
one element of the xml document with a new subtree (whose element name and
structure obviously has to reflect the dtd declarations as the element to
be substituted). I tried simply to substitute the NodeList with the new
one, but I saw that attribute is read-only and while I see method to create
elements, I don't see anything to *remove* something.. :-( How should I do
so?

Thanks as usual for the ones who can help me..  

-- 
bye
Alessio Pace