You can usually change the game files by overwriting them with the similar files from different developer/add-on. This is only valid for environmental files (as much as I know), engines cannot be swapped like this without editing rwtools.

This will not effect career scenarios, they will work as usual.

This method can be applied to any routes.

We will swap Donner Pass tracks with Soldier Pass tracks which looks much better in my opinion, see the screenshot of the guide. Also we will swap sky-box and weather files with Armstrong Powerhouse versions. And lastly, we will apply scenery upgrade from amazing workshop route Donner Pass Redux.

1- Open file explorer window and go to:

C:\Program Files (x86)\Steam\steamapps\common\RailWorks\Assets\RSC\DonnerPass

Steam folder might be different in your system, please see to it.

2- Right click on DonnerPassAssets.ap and select Open with and open the file with 7-zip.

3- From 7-zip window, we'll drag and drop into the Donner Pass windows some folders.

Extract folders:
Environment
RailNetwork
TimeOfDay
Weather

- Now we are ready to make first changes.

4- Open another file explorer window and go to:
C:\Program Files (x86)\Steam\steamapps\common\RailWorks\Assets\DTG\SoldierSummit

5- Right click on SoldierSummitAssets.ap file, open with 7-zip.

6- In 7-zip window, navigate to: RailNetwork\Track\ folder

7- In the Donner Pass window, navigate to RailNetwork\Track and from 7-zip window drag and drop the following files to the Donner Pass folder.

- SS_track_Main.bin
- SS_track_Main_W.XSec
- SS_track_Main_W_Cap.XSec

8- Now, rename the files above with the current folder track01 files.

Rename SS_track_Main.bin -> Track01.bin
Rename SS_track_Main_W.XSec -> Track01.XSec
Rename SS_track_Main_W_Cap.XSec -> Track01Cap.XSec

Before doing this, you might want to change the original files names to something different, like Track01.bin to Track01x.bin.


With this, mainline tracks has been changed in game.

Environment files

1- Navigate to following folder in Donner Pass window:

C:\Program Files (x86)\Steam\steamapps\common\RailWorks\Assets\RSC\DonnerPass\Environment\Sky

2- In an second window, go to the following folder:

C:\Program Files (x86)\Steam\steamapps\common\RailWorks\Assets\AP\WeatherEP\Environment\Sky

3- Copy from the second window both following items and paste into the Donner Pass folder:

Textures (folder)
skydome_1.GeoPcDx (file)

4- Overwrite anything that popups up and change the file name:

skydome_1.GeoPcDx -> sky.GeoPcDx

TimeOfDay files

5- Do the same for the TimeOfDay folder, replace the files in Donner Pass folder with AP files. They both have the same names, so you can just copy/paste and overwrite here.

Weather files
6- Copy the weather effects files from AP folder to Donner Pass and rename them to swap weather effects with the AP ones. You need all the files in the Texture folder from AP window also.

While replacing weather, you can get creative and change the foggy.bin with AP clear to thick fog file for example and could have a dynamic fog effect in your scenarios if they've been set foggy as weather.

1- Go to workshop, search and subscribe for Donner Pass Redux if you haven't already.

2- Start the game and go to workshop tab and wait for route to be installed.

3- Go to following folder for Donner Pass Redux files:

C:\Program Files (x86)\Steam\steamapps\common\RailWorks\Content\Routes\6ff8b604-7361-4193-9381-f15ac7984537

4- Copy the following folders:

- MixMap
- Scenery
- Terrain

Do not copy Networks folder as this will cause Tracks.bin error for the map career scenarios.

5- Paste these folder into the following folder:

C:\Program Files (x86)\Steam\steamapps\common\RailWorks\Content\Routes\00000032-0000-0000-0000-000000000000

I hope I am not breaking any rules by publishing this guide. If so, I can take it off immediately.