Allow the pot to cool for 20 or 30 minutes and then drain off the water. Rinse the yarn in water the same temperature as the water that was in the pot (even cold water can felt wool if it's warm). Allow it to drain a bit in the sink, then carefully wring out the excess water.
To get it even drier, roll the yarn up in an old towel and squeeze any remaining excess liquid out of the fibers. You can leave the yarn flat to dry or hang it from a hanger and leave it to dry in the shower in case it drips further.
Once the yarn is completely dry you can wind the hank into a ball and knit with it as you normally would.
Kool-Aid dyed yarns are relatively colorfast, but I have found that if you knit with them on bamboo or light wood needles, you might find a bit of the color rubs off onto the needles. This isn't a big problem as it will wash right off the needles if it bothers you.