lol.. and i was over my head wondering why i wasn't able do it with my camber board...
You can do it on a posi camber board. If you can do heelside and toeside stops, you can do this. I'll give an example for frontside spins.
1) Start doing the same motion for your heelside stops, but keep it going until you are in switch position
2) Immediately initiate your toeside stopping motion, but continue until you are in your regular position again
That's it! That's all there is to it. Progressively work up the speed and concentrate on making your spins fluid. This is also great practice for your edge control. Don't forget to always turn your head in the direction of the spin so you see where you are going.