Natural yeast in the juice will ferment the sugar to alcohol. Yeast need not be added, although it can without any problem. Some fermentation processes call for killing all the yeast in the pure cider with sulfur dioxide, waiting 24 hours and then adding wine yeast. For the homeowner this is not necessary. Put air lock on container and keep at 60-70F for a couple of months.
Lower temperatures take longer for product to change from sugar to alcohol.
Once juice is in container, the container cannot be moved as it will put sediment back into solution, and the results is a cloudy product. Beet, grape, raspberry juice, etc. can be added for color. Raisins can be added for sugar. This keeps the air space germ free and prevents off taste on the last used product.