When push comes to shove and a managerial appointment just isn't working out, saying goodbye and changing mid-season is often the right thing to do.It's harsh and quite often risky, with clubs most usually in the position hinging their survival hopes on the sack and switch. Managers aren't always easy to come by, though, particularly in making sure to find the right one.An interim or caretaker manager has the chance to book themselves into the main event, permanent role with a good performance on a stand-in basis. And while…