B&O Subwoofer help.

[50k]

Hi Guys

Just bought a B&O subwoofer with amp.
It is enclosed in a black casing and I presume the amp is housed within the casing (not sure) so my question is do I just remove the the old standard sub with its black housing and put the B&O one in or do I need to remove the black housing first?
The black housing around the sub a connection port seen in the attached picture so I would assume its just plug n play, but not sure.

I would really appreciate if you guys can point me in the right direction..

Edit: this is off a a4 b8 estate , my car is a a4 b8 saloon

 

[Audi.Quattro]

No amp in mine, just a 6 ohm speaker driven by the multichannel amp behind left side panel in boot, hence it's only got the speaker connector on it

 

[50k]

Guy told me on the phone it would fit but won't fit so going back to seller.
The sub in my car is a lot bigger than the one bought!