Q: Reinstalling Windows

I've been using Windows 10 without trouble for several months. Recently, I somehow locked myself out of admin authority, and there doesn't appear to be any way to get this back. Consulting a Windows forum, I was told that I may need to reinstall everything.

What's the easiest way to do this? Can I just download the ISO, put it on a USB, and boot up from there? I'm asking here just in case there are any additional steps or complications of which I should be aware.

Thank you!