Go into the header mode by clicking with your right mouse button on the header and choose “Edit Header”. To add custom information go to the “Insert” section under the Header & Footer tools tab on the ribbon and click “Quick parts”. In the menu choose “Field”. You will get a list of what you can add into your header. Find “Filename” from the list. Choose how you want the data to be formated. If you want the file path also then add check to “Add path to filename”. Press “OK” to finish.