Start the game go to new game or continue, then export and cloud save and export to file. Transfer the EK.bak file to desktop and import it the same way back again (new game, export and cloud, import from file)
For Android: EK.bak is in the main folder, you can transfer it via USB for example or send it via email. For import its also enough to have it in the download folder
For steam: copy the file to Documents folder and import it via game
iOS: no idea, don't have one, it works the same way but I don't know where it's stored or how to transfer it.