STEPS TO MODIFY NAVIGATION BY EDITING THE XML
1.Create a new solution
2.Add the site map to the new solution
3.Export the new solution
4.Extract the .ZIP file
5.Open the customization .xml file
6.Locate the Site Map node
7.Edit the map and save
8. Add modified .XML back to .ZIP file
9.Import the solution file
10. Publish the customizations
XRMTOOLBOX is the microsoft recommended tool for site map or if you are capable of editing and modifying the xml then OOB is the better option.
I hope this help someone cheers..