1. Get some cider. Best if you make your own. If you buy cider for this purpose, it should be unpasteurized. Some commercially-produced cider contains additives to keep it from fermenting. Jim and I once experimented with some organic cider from the food co-op, but even that would not ferment. I suggest starting with a small amount for your first batch, so that your heart is not broken if things don't end well.
2. Put your cider in the right container. Make sure everything is nice and clean. I have made hard cider in half-gallon growlers, gallon cider jugs, and five-gallon carboys. You can make hard cider in any container that will accommodate a fermentation lock.
3. Cap your cider with a fermentation lock. Shouldn't cost more than $5 even if you get a fancy one. Sometimes called an "airlock" or a "bubbler", should be available at a brewing supply store or online. The fermentation lock goes into a rubber stopper. Make sure you get a rubber stopper that fits properly into your container. Put water in your fermentation lock.
4. Watch. Fresh apple cider contains a small amount of naturally-occurring yeast. The yeast eat sugar and create two by-products: Alcohol and Carbon Dioxide. In a few days, the fermentation lock will start to bubble. The bubbles are carbon dioxide gas. You want to let the carbon dioxide escape without letting any other contaminants get in.
5. Drink. When the bubbles slow down the cider is finished. You may have a cider with 3 - 5% alcohol. If the cider is too dry or sour for your taste, try adding honey or sugar. If it's moldy or tastes foul, you should just throw it out. Sorry about that, it's an imperfect science.
6. Luckily, it is easy to make your hard cider Stronger, Faster, More Sanitary, More Predictable, and Suitable for Bottling.