Target Value to Remove (val): 6
ListNode dummy = new ListNode(-1, head);
ListNode curr = dummy;
while (curr.next != null) {
    if (curr.next.val == val) {
        curr.next = curr.next.next;
    } else {
        curr = curr.next;
    }
}
return dummy.next;
Initializing...
Step: 0 / 0