Inside the mounted ISO or the initial extracted folder, look for a folder named CODEX .
Verify you have all parts (e.g., part1, part2, part3) in the same folder. Redout.Space.Assault-CODEX.part3.rar
Go to the folder where you installed the game (e.g., C:\Games\Redout Space Assault ) and paste the copied files there. Inside the mounted ISO or the initial extracted
Double-click the game's executable (usually RedoutSpaceAssault.exe ) in the installation folder or use the desktop shortcut. Redout.Space.Assault-CODEX.part3.rar
Open the CODEX folder and copy all the files inside (usually includes an .exe and some .dll files).