The 'cone' induction kit replaces the restrictive air induction created with the typical ford system,just check the amount of plastic parts you remove when you fit a k&n or any other kit.
The air box contains your original air filter so is not required when you replace to an induction kit,its not used any more so might as well remove it if you want to.But you will need a crankcase breather unless your kit has a take off port for the breather pipe to your crankcase port at the back right hand side as you look at the engine.

ok so let me get this straight. if i keep the airbox. i dont need any more parts other then what comes with the cone itself

A couple of flexi cold air pipes help,cold air is denser than warm so helps with performance,without them your filter is breathing hot air from the engine bay not good ! your engine bay will look better without the airbox and lighter without all that plastic the crankcase breather is about £10 or less from halfords you wil need a 12mm size fitted in 30 seconds

Amanda.. when you get an induction kit, the airbox (the bit with Duratec ST on it) is useless. Some keep it to keep the look but there's no need whatsoever. When you fit the induction kit you'll get all the pipes and bits you'll need to fit it. The K&N fitting instructions (purely for example) are quite detailed and tell you what bits to take off and where to attach the K&N bits.