You've been here since Sept, so I figure you might already know this, but you asked a question that implies you don't:
Click on home, then click on "opt in" beside the tourney listing. That will take you to a page that lets you confirm you want to pay to opt in. Then click on Home again and refresh now and then. About 15 min before the tourney, you can click on "show password" next to the tourney list. That will open a new window with a countdown. You should refresh that at least once to sync the clock. Then don't drift off, because shortly before the tourney, the clock will be replaced by a "show password" button. Click on that and a 5-digit number will show up that you can use as the pw.