Once again, consistency in your basic flakas is a prerequisite here.
Pop as you would for a normal flaka, catch the nose and begin the backward slide.
Timing is crucial here- wait until you feel the board begin it's spin and take the front hand off the boom, moving it back to the clew end as in a duck gybe. If you let go too early, the board will carry on in a straight line backwards until it stops planing and you will fall in while being whipped around by the sail like a rag doll, much to the amusement of onlookers!
As the board rotates, reach around the boom with the old back hand, pulling the sail across yourself to stop the board over-rotating, and quickly get the sail under control in the clew-first position with both hands on the new side.
Sheet in, and flip the sail or gybe the board to sail off on a new tack.....................