Good general advice:
https://www.themuse.com/advice/can-we-talk-how-to-confront-someone-at-work
I am consistently surprised how awesome things tend to be for me, and as far as possible I always go straight to the source and cut to the chase in the interests of maximising everyone’s time.
In other words, I assume the wonderful quote from Grace Hopper:
It’s easier to ask for forgiveness than it is to get permission.