Help me prune my fruit trees

Hi. I'm new to the site and I'm at a loss as to how to prune my semi dwarf apple and pear trees. I've looked at lots of websites but im still afraid to hurt my trees. I have 4 apple and 2 pear trees. I'm located in Southern Ontario Canada and we are just coming into spring. Here are two pictures of one of my pear trees. One from the north and one from the west. Can I get some advise as to which branches the cut and where? Thanks

I like this guide: How to prune a fruit tree step by step