How do I wipe an external drive that I'm no longer using for backup?

I had been using a 2T external drive for the Time Machine backups on my iMac (running on Monterey), but I've connected a larger external drive to the computer and it's doing my Time Machine backups now. I wanted to wipe the old 2T drive so that I could use it for another purpose, but I'm running into difficulties. There are a few years' worth of backups on there, and I'd gotten rid of maybe the latest two months' worth (and had unlocked the computer's folder and given read-and-write permissions for what I assumed were all its contents) when I suddenly got told that some of the files didn't have the proper permissions. Am I now going to have to go each file (hundreds of thousands of them!) and individually unlock each one and give read-and-write permission before I can wipe this drive, or is there some way that I can just erase the whole drive without jumping through a series of hoops that could take me days or weeks to complete?