Do a search. There is tons of information on the subject. The general consensus is to leave it stock but replace the breather with an aftermarket one if it leaks. But if you must put the k & n filter thingy on, then use the stock tube that goes from the breather to the box (or one about that length), remove the box and hose that goes to the airbox. Place the filter at the end of the hose from the breather, zip ty the filter in the spot the box was under the seat.