just click on the Nissan app/logo, identify the vehicle then go to NATS, also sometimes found under service, once in nats the first step will be to read the( pin read ) this code needs to be generated into a 4 digit numeric code which you can find here click on this link,  http://bcm.keytechtools.com/  use the new code for  09 and up . the second step is to insert smart key in the slot located by the left lower part of dash beneath steering to the left and perform the steering lock release, this will erase all previous programmed keys and turn dash ligh on/ignition on. now the third and final step will be to perform the  c/u initialization , that will put the vehicle in learning mode to learn the keys, input the pincode again then right after press the brakes and  the push button and start vehicle. if it does not crank/start don't freak out, it will after this, key in the slot press push button to turn dash lights on/ignition on, don't try cranking, remove key from the slot, make sure ignition still on if not repeat until it stays on then press brake and start the engine.  turn on hazards lights on during the entire procedure to avoid from going into sleep mode.

note... sometimes the c/u initialization  function is not available with ignition off, in this case exit nats and re-enter nats with ignition on and it will be available.   this of-course is all  assuming your tool still has the nats functionality. hope this helps you.