Separate a rooster from hens?

I ordered 6 female chicks last year and 7 chicks were sent. All 7 survived and one turned out to be a rooster. Until recently we had no issues and he was a good boy. Lately he's been over mating my girls and has gotten really aggressive towards them. His spurs haven't really come in yet thankfully, but I'm sure it's only going to get worse.

These are my first chickens, and I've recently learned that a good ratio is 10 hens per rooster, but that is not an option for us.

Has anyone had success separating a single rooster from their hens? We are considering setting up a separate coop and run near our existing one and allowing him to free range during the day. But since these are our first chickens, we are definitely open to suggestions, aside from getting more hens.

Any suggestions or advice is welcome.

Thank you in advance.