Getting a behemoth like a novel manuscript ready for 'beta readers' - think of them as beta testers of your product - is a daunting task.
When I first began looking for help on how to slay the dragon I found a lot of advice online. But the process seemed like it was really difficult with many many rounds of editing. I was concerned that it was overcomplicating thing and keep looking for something simpler.
I kept trolling websites of authors and advisors and found that an article by 'Lewis' at on the Novel Smithy website really resonated. He shared that the editing process is really big and overwhelming so you need to find a way to break it into steps that you can understand, focus on (exclusively) and execute.
Okay, that made sense to me. that's why there are so many steps in these author processes. Because it's complex and broad and voluminous work to edit a book. It's also different for different authors and there are subtle differences in their choices, but generally speaking there is a big to little approach that seems pretty universal. first deal with macro structure of the book working your way down to do I put a comma before or after that word. Don't try to do two things at once with an edit or you will probably do both half way.
Going back to Novel Smithy, the process he outlined was decidedly analytical. I could easily envision a spread sheet or tracking file to go along with it. So if methodical work is your jam, it's probably a great place to start.
Other authors us a less methodical but still focused and step by step method. Gotham Writers Workshop (Great group I'll write about later). Has a nice writers resource area and that's where I saw Jessica Sticklor's article on The Ten Revision Stages of a Novel. Again breaking it down to smaller more focused pieces but this time from a more literary perspective.
What I have walked away with so far is that editing a big document is a series of small event not one big one... at least if you want to succeed. And, there is some trial and error finding the process that works for you.