Yeah, I had a hard time finding where to do that, the link in the email doesn't take you to it. You go to "MY ACCOUNT" then click the edit tab, it will let you change it there.
I'm hearing from some folks that the log-in/password fandango isn't exactly intuitive.
When you create an account/register, run back and check the email address you signed up with to get your one time password. Come back, log in with that password, and change it to something you know and love.
and if that doesn't work out for you, let us know.