I'm working on an audio book about history, and I've decided to have the audio book recited as a monologue, to make it somewhat more engaging, but I've written the original draft for the book as a narrative. What is the best way to go about converting a narrative to a monologue without adding too many words to the whole thing, but still preserving as many facts and points as possible? The original narrative doesn't contain too many sustained characters I can play off of, but it is reasonably chronologically coherent.
The simplest answer would be to try writing it like you're telling it to someone. You could use a "rubber duck" method to test it out: Place a rubber duck (or something similar) next to your computer or wherever you write, pretend it's a person, and try to explain the manuscript to it from your point of view. Make sure to insert your personal reactions/feeling on things, don't just read the script. Make it conversational. That should give you a good idea of where to start regarding the style of writing.
From there you shouldn't have to rewrite too much, you'll mostly be changing little phrases here and there to reflect the first-person view.