The big black round hole is where the air is sucked into the engine. The thinner piping that is shown in your pic needs to be connected to the underside of the airbox.
If you pull smartly up at each of the corners of the airbox, it will come away easily. The thin pipe will fit onto a plastic hole sort of thing on the right hand side on the underneath of the box. There should be another pipe which connects at the rear of the airbox - best to check this is also securely connected!
Once all connected, push the airbox back into its four mounting holes.
Hope this helps!
