Easila

Hi all. New in the forum and also with the ford edge. I have the 2009 edge DEL. I changed the old stereo system to a new Android sound system . Can't find the diagrams on how to connect the sound system to the steering wheel control . Now - due to the fact that the old system wasn't connected as well I am a bit puzzled. Can anyone help me with this ? Managed to connect everything else but this attribute. Thank you all in advance.