Yeah, the event's been over for quite a while. Just wait for the next EX3 event 17 days for now. The more participants, the better.
Just create an account at www.residentevil.net or log-in with a Facebook or Capcom-Unity account. Link your save file with your account at RE.NET, turn on auto data upload in the options and you're done.
Play the requirements of the specific event going on while your console is connected to the Internet.