Removing stray Time Machine folder

When I was having trouble with Time Machine a few months ago (which I traced to the external drive manufacturer's 'helper' application, since removed), I somehow wound up with a Time Machine backup folder on the root level of my main hard drive.

I browsed that folder tree, and there is nothing backed up within that folder. Just to keep things clean, I would like to remove this stray folder, but the system permissions have locked down this folder tree such that I can only read.

Checking in System Preferences shows that the system does not currently have the main drive itself selected as a backup location.

It's probably not hurting anything as it is, but again, wanting to keep things clean and avoid issues down the line, I'd like to remove that empty folder tree. How can I temporarily override the permissions to clean this up?