How to update an existing XML document

["Ponakala, Malathi (Indsys)" <Malathi.Ponakala@ge.com>]

Hi,
 Can any one guide me in processing an existing XML document to insert new
nodes, delete existing nodes and update the data in random order ,  using
Xerces parser for Java.
If you could provide required classes and methods it would be much more help
full.

Thanks in advance,
Malathi.