Should we tell the kids we're changing the schedule?

My ex and I finally agreed on switching from 5/2 to 50/50 starting next month. We're both nervous about how to tell the kids (7, 10, 13) without making it seem like a huge deal but also acknowledging it's a change. My 13yo is definitely gonna have opinions lol. Are we supposed to tell them together, separately, in advance, like a week before? What did y'all do? Want to get this right because they've been asking more questions about why the schedule is what it is.