There are many ways to participate. First, sign up at the above site if it appeals to you.
I chose to go to talkshoe.com and enter an ID number. There is a choice of Sufi, Insight, or Jeddah Mali/Interdenominational meditation. I believe it takes about forty minutes and is a simple guiding in and out, which will deepen through the forty days.
You can listen at any time, though early is a lovely and peaceful way to begin the day.