After sign up, you will receive an email from SH. You go to the HP site, log in and choose the upgrade option you want, and do payment. But you can only go in once, so once you're in, don't change your mind and log out -will not be able to log in again!
After that HP will give you a call to confirm your order. Then a few days after the logistics company will call you up and tell you when to collect.
I got mine on Tuesday already