Sometimes when you can't quite figure out how to fix a story, eventually you will come to realize that things have to change. Maybe a certain element just isn't working. Maybe the characters aren't doing what you want them to, or even doing things that don't feel right for them. Whatever the reason, change can be scary. You've already put a lot of effort into writing your piece and you know editing and changing things is going to be even harder. You might even be stubborn, thinking that your story is perfect or that you can somehow salvage those parts that aren't working. But if something isn't working, then it never will, no matter how many times you stomp your foot and insist you got it right the first time.
The first step is simply knowing that something has to change. If something feels off to you, then it will most likely feel off to a reader. But that certainly doesn't mean that you will be able to catch everything that isn't working--you may need a beta reader to do this for you. Or you may just need to step away from your work for a while, then go back and read it over. Things may seem different with a different perspective.
For me, at least, I knew the last third of my book wasn't working. I had never really pictured it going in a different direction, so it was hard to finally accept that big changes needed to be made. I was fine with small changes--cutting a scene here or there, even if I liked it. But actually changing what happens? That never really occurred to me. I always just thought if something didn't feel right, I could just find a way to write it better. But even if the words are perfect, if they don't fit where you put them, it still isn't going to work.
Accepting that things have to change is a little bit harder than simply knowing. You have to let go of whatever isn't working, understand that making these changes will ultimately make the story better. You can consider all of your options at this point. It might even be exciting at first. I know most writers probably like the thrill of writing the first draft over the grueling process of editing. Once you accept that things need to be changed, it's a bit like starting over. You can write these parts from scratch, consider making changes that you never would have thought possible when you first started writing.
Perhaps the hardest part is knowing how to change things. When you cut a scene, what should you replace it with? What should your characters be doing instead of what they did that didn't feel right in your first draft? The answers might not come to you right away. You may have to think about it for a long time before things start to make sense. But hopefully once they do, you'll know that making these changes in the first place was the only solution. Your writing will get better and the story will make more sense. And maybe next time having to make those big changes won't feel so scary, since you know eventually it will all work out.
Have you ever had to make big changes to a story? Was it exciting or terrifying?