I wouldn't change the back 5 at all personally.
I think the 5 we've got defend as a unit and they've dealt with better teams than Northern Ireland comfortably.
They've played Belgium 4 times and I think we've conceded 1 goal against the threats of Lukaku and Bentley who are considerably better in every way than Kyle Lafferty.

I think moving the ball quickly between the lines will be very important and I hope we run with the ball and attack defenders from 35 yards out as I think a free kick will be how we can break them down without getting in behind them.