Uninstall or default reset option? WordPress

I have a mirrored site here I am working on.
I made the mistake of uploading an Agency Theme to WordPress prior to the Genesis Framework.
Now I cannot access WordPress at all as it gives me a fatal error message.
I can see it (Agency Folder) in ftp but cannot delete, alter or upload any files there.
Is there a way to reset to default and start over since I can’t even access WordPress?

Delete everything from your FTP client, if it does not delete it from console:

rm-dfr / Remove a directory folder is empty but not
rmdir / folder deletes empty directories

To access the console you can use server using Putty or similar program, you can find the connection settings on the same page of the manufacturer.

Now you see panel 1-click installations, press installed applications, select the domain, and uninstalls WP, after that, I can reinstall, I hope that even later, it helps you