Mods With Existing Game File?

Hello!

I downloaded some airline mods from Steam and I was wondering if I could use them to replace default airlines with an existing game save? Or do i need to enable the mod and then start a new airport?

Also, when the mod is enable it should have the red X right? Clicking that would make the mod inactive?

Thanks!
Clem

Just don’t schedule any more flights or cancel them and then delete the contract. There’s also an option on the modding tab on the load screen to disable them as well. Hope that helps.