Edit Compiled Lesson?

I'm new to Storyline, but was a Flash author for a decade and have a very good understanding of the Flash aspect and restrictions of Storyline presentations. That being said, I started a new job where I'm finding out that my predecessor did not save his .story files and he has left the company. Turns out that there's an error on one of the lessons that he created and I've been asked to fix. Before I go and reinvent the wheel by recreating from scratch, I need to ask if there's any way to edit a Storyline 2 presentation that's already been compiled and without having the .story file.