Editing files outside the Workbench
To edit a Workbench resource outside the Workbench:
  - Navigate in the file system to the Workbench's installation directory. Go 
    into the workspace directory and open the file that you want to edit with 
    the external editor.
 
  - Edit the file as needed. Save and close it as usual.
 
  - Important: Go back to the Workbench, right-click the edited file 
    in one of the navigation views, and select Refresh from the pop-up 
    menu. The Workbench will perform any necessary build or update operations 
    to process the changes that you made outside the Workbench.
 
Tip: If you work with external editors regularly, you may want to 
  enable auto-refresh. This can be done by opening the
  
  
  General > Workspace preference page, and checking 
  the Refresh automatically option. When this option is enabled, 
  any external changes will be automatically discovered by the Workbench. Depending 
  on the platform this may not happen immediately.

Editors
External editors

Opening files for editing
Associating editors with file types