Preheat the water in the Sous Vide to 120F for dark chocolate or 105F for milk or white chocolate (suggest trying 110 for milk)
Place vacuum packed chocolate in water bath and let sit until totally melted.
Once melted, reduce temperature to 81F by adding cold water or ice to the bath.
Once it hits 81 F, increase the temperature to 90F for dark chocolate or 86 for white or milk chocolate (try 90 for milk chocolate as 86 seemed too thick). As chocolate rises in temperature, squeeze the bag several times. This is necessary to line up the fat crystals which is the whole point of tempering.
Chocolate can be left in the waterbath at final temperature for many hours. I've heard as much as 12 hours, maybe longer. As long as it stays at that temperature, the chocolate will remain tempered.
When you're done, reseal the bag and remaining chocolate can be reused/retemperted another time.