I have spent many years as a GM and now I want to switch to head coaching. How do I switch to head coaching? I've tried calling around, but I'm given no option to call any team around once it gets around to staff hiring. I have also tried creating a new game and selecting head coach in challenge mode, but it is greyed out where I can't choose which role to play.

You have to play in "local mode" in the league setup. This allows you to determine if you can be a GM or HC or if you play in "global mode" you are just the GM who can control the HC duties if you want to.

Thank you!