First note that the LinkedList class is already available in the JDK, and directly provides the .stream() method. I would recommend using this standard implementation if possible.

If you still want to use your custom class ListNode, a good way to obtain a stream from it is to :

1. make ListNode implement java.lang.Iterable interface,
2. call StreamSupport.stream(listNodeInstance.spliterator(), false)

You can use a Collector like this to put the result into a LinkedList:

LinkedList<String> usernames2 = 
       users.stream()
            .map(User::getUsername)
            .collect(Collectors.toCollection(LinkedList::new));

You can use the other reduce operator, doing

    static Node reverse(List<Integer> list) {
      return list.stream()
        .reduce(
          (Node) null, //the empty element
          (n, i) -> new Node(i, n) , //combining a Node and an Integer
          (n1, n2) -> new Node(n1.value, n2)); // could be anything
    }

Edit: To make it work with parallelStream:

    public static Node merge(Node n1, Node n2) {
        if (n1 == null) {
            return n2;
        } else {
            return new Node(n1.value, merge(n1.next, n2));
        }
    }

    static Node reverse(List<Integer> list) {
      return list.stream()
        .reduce(
          (Node) null, //the empty element
          (n, i) -> new Node(i, n) , //combining a Node and an Integer
          (n1, n2) -> merge(n1, n2)); // combining two Nodes
    }