When you need to make changes to your user DFS environment, a tool like dfsutil.exe is your friend.
Latest when you want to replace your old Windows Server 2003 File and Distributed File Service, you will be faced to add or change the DFS target links or their properties.
Export your DFS environment with dfsutil.exe first:
dfsutil root export /? shows you the possible syntax.
Now you modify the exported file content.
Then you delete all targets.
Next step is to import your modified export file:
dfsutil root import merge /? shows you the possible syntax.