get a carton of apple juice (cheap supermarket brand will do) and pour it in. try and keep it at a stable temp of around 20 degrees. give it a gentle swirl every now and then and with a bit of luck that yeast will come to life in a couple days. once its away and fermenting add another carton. don't tighten the top down, jost losse will do as you dont want the bottle to explode. with a bit of luck in a couple weeks you will have a turbo cider
if it hasn't fermented your apple juice will be fine to drink stil. so you wont lose anything