Eight random security keys for wp-config.php. Everything happens right here in your browser; nothing is ever uploaded or sent anywhere.
Where these go: replace the matching eight define() lines in wp-config.php with what's above. A couple of things worth knowing: changing these on a live site logs everyone out, since it invalidates existing login cookies. That's harmless, but do it when that's not disruptive. And generate a new set for every site; never reuse one set across multiple installs. Nothing here is uploaded. These are generated using your browser's cryptographic random number generator and never leave the page.
No pitch, no pressure. Just talk about where you want to go.