The format for the heelflip is almost identical to the classic kickflip except that flicking the board with your heel can be a little more tedious.  Now your set up with your back foot is going to be in the same ollie position, but you are going to move your front so the ball of your foot is slightly off the board.  Remember to place the front foot a couple inches behind the front bolts.

You want to execute the heelflip the same as the kickflip, except it is obviously done with your heel.  I found the easiest place to flick the board is right on the wheels where it scoops down.  Then all you need to do is stomp it and ride away.  This trick took me some time to get used to, so be patient, you’ll get it!