blockchain.info hybrid paper wallet tutorial troubles...(yes I'm a noob)

[bitlizard]

I'm having trouble using the paper wallet tutorial on blockchain.info https://blockchain.info/wallet/paper-tutorial

I have successfully:
- generated a new public address in private browsing offline mode
- generated qr codes for all my addresses including the one made in offline mode
- generated what I think are public and private keys along with the qr codes
 
Step 5.  Delete the private keys

How the F do I do this?
where are the private keys?
if I generated them in private browsing offline mode via java script don't just vanish when I end the session?
what is the difference between a wallet.dat file and a private key?

Any help would be really appreciated

[jago25_98]

Somebody made this guy a vid. I can't, net's too slow

[deus-ex-machina]

Made a video.
http://www.youtube.com/watch?v=M6MaEBk41H4

[bitlizard]

cool video thanks.