In order to take over a new club you have to open the Job Centre feature, choose a club from the list and click on Take over, you will then see a POP UP message that explains this feature and warns you that this action would be permanent. If you click "Yes", you will see another POP UP message that says "There is no going back after this step", "Type the following step in the field to switch the clubs". And once you type the text in the tab you can take over the club.