You don't actually have to print it.You can check in online but not print it. Then when you get to the airport hit the self check in kiosk and it will then print your boarding pass in the same group you checked in online with. Found this out from a friend the last time he went. We got stuck with the C passes the last time we went.
The best thing I did on this past trip was just check in via the web on my phone. By using the confirmation numbers, I was able to check in exactly 24 hours in advance and get everything all set there. Then, at the airport, just print out your passes when checking in your bags. It was so much easier and I was able to get this done without having to ensure I was at the hotel at the 24 hour mark