Addon installation:

1. Open your Grand Theft Auto 5 folder
2. Navigate to mods > update > x64 > dlcpacks
3. Place "brownstreak" into "dlcpacks"
4. Load up OpenIV and navigate to mods > update >update.rpf > common > data
6. Extract "dlclist.xml"
7. Paste this line into the list:                 <Item>dlcpacks:\brownstreak\</Item>
8. Place "dlclist.xml" back to where it was

Train configuration installation:

1. In OpenIV, navigate to mods > common.rpf > data > levels > gta5
2. Take "trains.xml" from either one of the two "train config" folders (recommended: "train config - freight and streak mixed") and place it there.
3. Lastly, take both files from the "train stations" folder and place them in the same folder from step 1.

(Optional) Railroad Engineer configuration installation:

Place J10RailroadEngineer.ini into the GTA V root folder and replace the original. This simply adds the loco to the config and thus makes it driveable.