Securely wipe old time capsule
I've just bought a latest gen airport extreme, to replace my old 3rd gen time capsule. Plugged in AE and ran through the airport utility to replace it. Must say what a seemless process, typical Apple, great to be able to run like this rather than manual.
So all working fine, but now as my time capsule isn't it used I want to securely wipe it to sell it on. I know there is a little reset button to press, but will this securely get rid of my backups? I'd rather be safe and wipe properly.
Can I still do this now it isn't part of my network? What's the procedure please
Thanks
iMac, OS X El Capitan (10.11)