well if you arent trying to do it late yet... then..
1) get ready to do a nollie, yet with your front finger slightly closer to the edge near you, kinda between the dip and the middle of the nose kick. Your front finger can be well.... however it works for you.
2)pop just like a regular nollie BUT BUT BUT while you are poppin'
curl that front finger and kind of push it down and while you are doing that well just start doing that motion where you make a nollie actually get air with your back finger.
3) when the board gets off of the ground it will start to flip so peel your wrist up and your fingers off of the board. and then catch it like a nollie flip.
4)practice practice practice until you are comfortable then you can add the late-ness to ito
5)there is no step 5
6)be