Sterilize all the equipment with the bleach solution. Completely fill the carboy and submerge in the solution and allow to sit for 10 minutes. Thoroughly rinse off the solution.

Add 1 gallon of cider to a large pot and heat to 120°F. Stir in the brown sugar until dissolved. Turn of the heat and allow to cool to 105°F.

Place 1/2 cup of the heated cider in a small bowl and set aside. Add the rest of the cider to the carboy along with the other two gallons.

When the small bowl of cider is between 100°F and 105°F, add the yeast and give it a stir. Let it sit for about 15 minutes and you should see it beginning to foam a little. That tells you that the yeast had been activated and is ready to pitch.

Pour the yeast into the carboy and cap with an airlock or cover with a napkin and rubber band. Allow to ferment for 10 days.

At this point the hard cider is potable but it is best if allowed to age for 3 to 6 months.

If you prefer something with a little more kick, you can turn this hard cider into applejack. Since distilling your own spirits is illegal, I will not explain how to do it here. Just Google the term, "freezer distilling" and you will find all kinds of information on how to do it.