How to remove dark gray background from dark gray photo?

I am a student at a university and I need, for a project, the profile contour of a personality in a dark grey picture with a dark grey background.

I need the contour and the his signiture for the project but i can^t get it done. I have watch several tutorials on youtube on selecting hair, removing background etc. but the pictures they use are very easy to do (because they are tutorials).

My question is: how can I cut out the man in the picture and his signiture and eliminate the background so I can use it in Fireworks for the project I need (in Fireworks I need to put another picture at his back)?

Thank you very much !

this is the url of the picture:http://ift.tt/1Ccs3AA