The funniest thing I find about my history and Helpdesk is the credibility. Yes I can talk your language and I know your priorities and I know what worries you about technical change. I know the results of an outage because I have had to support it. I took the calls and I took them for a decade.
I know exactly what it means to fail. Which is something you should understand when you make a change for IT Security.
They don't need to hear perfection. They need to hear empathy. They need to know you thought this out and that you know exactly what will mean if it fails. Because you sat on that call. The thousands of them.
Failure is pain. And they need to hear that in your voice when you tell them the plan about changing everything.