Removing casing around radio - old shape astra

[matrix3412]

I am trying to fit an mp3 player into a 1995/6 vauxhall astra. I have managed to remove the radio but there is a black metal casing where the radio was fitted. Does anyone know how I can remove that so I can get the mp3 player in properly, as with it left in, the mp3 player won't go in all the way?

Thank you

 

[matrix3412]

Thanks for the quick replies

I looked and looked for a screw somewhere but I couldn't see one so I might try ripping it out.

Thanks again for the suggestions