what you bought was an apexi pod with a stock nissan air flow meter attatched. what you have is a K&N pod with a stock nissan air flow meter attatched. its the same unit. why remove something if it aint broke?
separate the apexi and its afm, sell this afm, remove K&N from car (leave the original afm in car), put apexi onto original afm, sell/chuck K&N.
EDIT: just to make this a bit clearer to you dude go check out apexi's website. they sell the power intake and also a super suction kit which is intended to replace your afm but do not include it in the kit. in fact im pretty sure apexi or K&N never made an afm (i may b wrong). therefore you cannot buy a new pod that comes with an afm. you have bought a second hand one that wasnt separated from the afm it was originally bolted to