Pruning fruit trees is one of those garden tasks that is hard to pick up from a book. It's best to learn it directly from an expert in the orchard, ideally by making a few cuts yourself. Whether you are a home orchardist, a Star Wars fan, or both, there's something to make you happy in this short instructional video. May the pruning force be with you!

(for general info on the pruning of apple trees, this link may be of interest)