private static void Traverse(string top, string from, string to)

        {

             SPSite topSite;

             SPWebCollection subSites;

            try

            {

                topSite = new SPSite(top);

                subSites = topSite.AllWebs;

                foreach (SPWeb web in subSites)

                {

                    using (web)

                    {

                        Console.WriteLine("******** STARTING " + web.Name.ToString() + "************");

                        SPNavigationNodeCollection nodes = web.Navigation.QuickLaunch;

                        foreach (SPNavigationNode node in nodes)

                        {

                            UpdateURL(node, from, to);

                            SPNavigationNodeCollection childNodes = node.Children;

                            foreach (SPNavigationNode cNode in childNodes)

                            {

                                UpdateURL(cNode, from, to);

                            }

                        }

                        Console.WriteLine("******** CLOSING " + web.Name.ToString() + "************");

                    }

                }

              //  Console.ReadLine();

            }

            catch (Exception exp)

            {

                Console.WriteLine(exp.Message + " :: " + exp.StackTrace.ToString());

            }

        }

        private static void UpdateURL(SPNavigationNode cNode, string from, string to)

        {

            if (cNode.Url.IndexOf(from) > 0)

            {

                Console.WriteLine("FOUND CULPRIT -> " + cNode.Title.ToString() + " :: " + cNode.Url.ToString());

                cNode.Url = cNode.Url.ToString().Replace(from, to);

                cNode.Update();

                Console.WriteLine(cNode.Title.ToString() + " :: " + cNode.Url.ToString());

            }

        }