Basically, you open the route for edit in Trainz Content Manager, apply the TransDEM function(s) to make your adjustments, then commit the route in Content Manager again.
- Check the common edit folder where both Content Manager and TransDEM place their routes. Make sure your route does not exist in this folder. Delete or move such a route with the same name elsewhere, if you find it there.
- In Trainz Content Manager, open the route for edit.
- In TransDEM, apply the function(s) to modify your route. If it's about adding UTM tiles or vector data, process as you would when creating a route but do not run the the initial terrain and ground texture exporter again. The other helper functions are found in the Trainz menu as well. Keep in mind that some of them require a route that has been created by TransDEM in the first place, but these two functions should work with any route: Adjust elevations (height) and Remove ground textures.
- In Trainz Content Manager, commit the (modified) route.