How to reinstall windows 10 for boot camp

So I’m currently trying to get Windows 10 on my iMac w/ high Sierra and I was wondering if I could reinstall the windows installation because when I clicked which OS I wanted for Windows 10 (during the installation on windows where it lists a bunch of OS) I clicked the wrong OS (I clicked Windows 10 S instead of Windows 10 Home) and I can’t go back and install the right one. Do I have to go back into the boot camp download and let it take up another 40 GB of space for another installation?