Writers, from what I’ve experienced, tend to be pack rats by nature. We hold on to a lot of things, from old knick-knacks to old photos, and especially old manuscripts. I have yet to meet a fellow author who’s said “Yup, I destroyed all my old stories completely.” Even if they never see the light of day, for whatever reason, we keep the old things around. And time, let’s face it, is not always kind to old ideas.
However, an equally undeniable fact is that some ideas do hold up to the test of time. Flash Gordon remains a cult classic just as much for its simplistic presentation as for its high-octane camp. Fans continue to clamor for more Star Wars even though the first movie premiered over 35 years ago. It’s entirely possible that one of those old manuscripts holds a core element or key idea that can be planted in fresh, unwritten soil, to grow into something entirely new. Or, to go with a more carnivorous analogy, the meat may be rotten but the bones are intact. And the bones can use used as stock for something new and delicious.
But first, all of that old meat has to come off.
It can be difficult to strip an old story down to its bare elements, to delete thousands upon thousands of words that you might have spent hours or even days working on. But it has to be done. Hopefully, you are not the writer you were years ago. You’ve grown, learned, and gotten more used to your voice and your pace. You know what makes good characters, be they heroes or villains or some poor schmuck caught in the middle. Your descriptions are no longer than they have to be. You keep it simple. You grab the reader by the scruff. You kill your darlings.
Any meat of the old stories that doesn’t do the above can come off of the bones.
It’s messy work. It can take a while. And it’s one thing to kill a darling; it’s another to dismember it, to rend it to pieces that your dog might find questionable. But it has to be done. What else is that old manuscript going to do for you?
Be you starved for a new idea or wondering how you can make an old one work better, to create you must first destroy. Get the rotten meat off those bones, then boil them in the clean water of a fresh and cleared mind. Start a new outline. Drop in the bones (the plot points & ideas) and build something new around them. You might be surprised at the results.
That’s how I’d go about it, at least.