You can import profile without deleting an existing one. But if you want do this go to Documents\My Games\TrainSimWorld3\Saved and delete the 'SaveGames' folder. If you have more than 1 profile you can delete one of them ingame.
RESOLVED If you go into my games and delete the profiles you may (I did ) set up which are in the saved game folders then the rest of whats contained here works. https://live.dovetailgames.com/live...95.439835179.1662102982-1095375953.1615309706 Thanks PseudoStalker , think we literally just posted the same time.