final ClList nsElem = getNamespaceElement();
if (nsElem != null) {
final ClSymbol first = nsElem.getFirstSymbol();
final PsiElement second = nsElem.getSecondNonLeafElement();
if (first != null && second != null) {
final ClojurePsiFactory factory = ClojurePsiFactory.getInstance(getProject());
final ASTNode newNode = factory.createSymbolNodeFromText(newNs);
final ASTNode parentNode = nsElem.getNode();
if (parentNode != null) {
parentNode.replaceChild(second.getNode(), newNode);
}
}