Riding switch is riding with your non-natural foot forward. If you are goofy, left foot forward is riding switch.

To turn the board to switch start off with a flat board with a fairly even weight on each foot and bend your knees as much as you can.

Slowly bring the handle from your leading hip out in front of you keeping your knees bent, binging the board to a board slide position (90 degrees) for a second, then carry on moving the handle so that it is in line with your other hip.