I regularly change my city’s layout all the time. I usually move all my tall buildings to one side of the city to clear everywhere else and then delete all the roads there and start moving things and building roads back where I want. it can’t be a pain in the butt, but it gets the job done. if you’re worried about population happiness, you can try just putting small services e.g. police etc, over there where you put the buildings to mitigate the happiness level but their happiness goes right back after you put the buildings back. I’ve gone as far as deleting every residential building that I have in a city and start from scratch