A track editor (Forza Horizon 4)

All kind time of day. Haven't found any information on my questions, because to create a theme. And here's a question: after you create your race, as it is, in fact, to remove or edit? I made a mistake, for example, by choosing not the best weather conditions, or want to change the class of car. About the editor the route I am silent, this is only possible in a dream world, but the rest? Maybe I somewhere not there look, but have accumulated these testing enough already, I would like to clean