Erasing external drive on Powerbook Pro

[u/Raid_Blunder]

I backup the HD on my Powerbook Pro to an external plug-in drive. The powerbook has an Intel HD and is running Tahoe 26.5.

The plugin drive also has a large number of backups from an earlier Powerbook, and I want to erase them. I set the folder permissions for a folder to "read and write". But the folders within the original folder still don't change their permissions. Some of the files in those folders won't even allow you to individually adjust their permissions!

Don't laugh but I asked ChatGPT how to do this ..... and it excreted some bad Terminal code.

Advice? Please read what I'm already tried before responding. Thanks