Manipulating DOM Elements of Storyline Content's Published Output

I have some published content for which I do not have the source files. I have some experience with HTML, Javascript, and CSS (not a ton). I've seen that sometimes people have been able to manipulate the output for their project. One of our published products has an error in it that I would like to fix, but, without the source, I can't republish and re-upload to our portal. I don't need to change the style of elements. In fact, I would like these to just remain as is. Instead, I want to change the text of an HTML element. When I hover over the element I want, I see it's in a canvas, which I assume means it just draws a graphic, rather than the text being an HTML text element like a <p>? I've provide an image. Is there a way to manipulate this graphic? I basically just need to change the text "suppress shivering" to "Move to a warm area."