Everything you've done thus far has been private. It helped to know that these were good people who were invested in doing a better job. I was counting on them to have the same epiphany that I'd had. When you take center stage, avoid throat clearing. Get your message out.
Indirection creates tension.
Within the first minute, you should be into your message. Make your point. And then stop. Step back and give the listener some time to react. You've probably spent weeks thinking about this problem.