See approach of working with kXML2 open source library:
for release you have to preverify it & build proj with ant:
Ahmad Ferdous Bin Alam - How to Import kxml jar File to Your Project
Slashdev - BlackBerry Development with Ant & Eclipse UPDATE:Tutorial: How To Use 3rd Party Libraries in your Applications
for debug you have to add kXML sources and org.xmlpull.v1 sources to your BB project