He has done two things:
1) Get the spirit of the club and tune it so that there is a togetherness about players, fans, and management - that is the most difficult thing to do.
2) Making the decisions whenever possible with regard to putting the jigsaw pieces of the team together - without being a stubborn manager, essentially fixing those things about the team that we as supporters have known or know are just don't work - e.g. Karius and other players he got rid to get better players in and buying the right players.