How to manually downgrade Fallout 4 and install Fallout London on Steam

✓ At a glance

• You have to downgrade Fallout 4 to before next-gen version to be able to install Fallout London.
• You can use a mod to do it, or manually by using the Steam console to download older files, then replacing them within Steam.
• After downgrading Fallout 4, install Fallout London by downloading the files from GOG, unpacking, and using an installer to complete the process.

With Fallout London, a huge overhaul mod for Fallout 4, needing several extra steps to install, some of us aren’t looking for gimmicky installers and prefer to do things manually. Call that good old trust issues, but having to deal with Nexus Mods downgrader doesn’t inspire confidence. Fortunately, team Folon has graciously set up a way around that. We’ll take you through the manual downgrade process step by step, so just follow along.

How to manually downgrade Fallout 4 on Steam

To begin with, you will need Fallout 4 with all DLC or the GOTY edition installed to be able to play Fallout London. If you’re playing through Steam, then downgrading to pre-next-gen version is a bit tricky and there’s no straightforward way to do it manually. So let’s go through the required steps:

Step 1: Access the Steam console

To begin the process, we need to access the Steam console. Open your browser and in the address bar type: 

• steam://open/console

This step will prompt Steam to open the console and allow us to download the necessary files. If the browser asks for permission to open an outside app, Steam in this case, select that you agree.

Step 2: Download the main game files

The previous step will launch Steam and open the console window. You’ll find a text box at the bottom of the screen. We’ll need to download the main game files through the console. Input the following commands in order:

Download part	String to copy/paste
Part A	download_depot 377160 377161 7497069378349273908
Part B	download_depot 377160 377163 5819088023757897745
Executable file	download_depot 377160 377162 5847529232406005096
English version	download_depot 377160 377164 2178106366609958945

Step 3: Download DLC files

You will also need downgraded files for the game’s DLCs. In the same console, input these commands to get the DLC files:

Download part	String to copy/paste
HD Texture pack	download_depot 377160 540810 1558929737289295473
Automatron	download_depot 377160 435870 1691678129192680960
Automatron English language pack	download_depot 377160 435871 5106118861901111234
Wasteland Workshop	download_depot 377160 435880 1255562923187931216
Far Harbor	download_depot 377160 435881 1207717296920736193
Far Harbor English language pack	download_depot 377160 435882 8482181819175811242
Contraptions Workshop	download_depot 377160 480630 5527412439359349504
Vault-Tec Workshop	download_depot 377160 480631 6588493486198824788
Vault-Tec Workshop English language pack	download_depot 377160 393885 5000262035721758737
Nuka World	download_depot 377160 490650 4873048792354485093
Nuka World English language pack	download_depot 377160 393895 7677765994120765493

Step 4: Replace the Fallout 4 files

All of the above files will be downloaded to your Steam library folder. By default, this will be in:

• C:\Program Files (x86)\Steam\steamapps\content\app_377160

Each of the depots will have its own separate folder within the one above. The next step is to create a new folder, for example on your desktop. Copy the files from each of the downloaded depots one by one. If any files ask to be replaced, choose Yes. This will in essence create a fully reconstructed Fallout 4 without the next-gen update.

Locate the Fallout 4 installation folder within Steam and delete everything in it. Then, copy all the files from the newly created folder into that one.

Step 5: Disable auto-update

The last step is to prevent Steam from updating Fallout 4 and undoing your work so far. Within the Steamapps folder on your system, search for the file called appmanifest_377160.acf and right-click on it. Select Properties and tick the Read-only box, then press OK. With that, your Fallout 4 copy is prepared for the installation of Fallout London.

How to manually install Fallout London

After completing the downgrade described above, it is time to manually install Fallout London. Download the required DRM files through GOG, perform the “installation” and you will find them in the GOG download folder. All the necessary installation files will be inside, including F4SE and Data folders.

You can use the Data folder to zip and add to your mod manager of choice. If you want to install Fallout London manually, then locate the Installer.exe file and run it. This will perform the necessary installation of the mod, without the need for a mod manager.