And you know what, firing is DEFINITELY not the first option on the table! Have those tough grown up conversations to talk about what’s not working, what you would expect to see changed and agree on what they’ll try differently (and how you will support). Of course that’s the first approach.
But sometimes… you HAVE to be willing to be the bad guy and get someone off your team, even though it feels like crap. And of course HUGE disclaimer here, before going down this route you MUST check in with your local employment legislation to ensure you're doing it the right way.