My life for the last year and a half has been all about this very topic. Indeed, the reason I've put off writing this post is because I'm immersed in trying to clean/organize/wrestle into shape an old manuscript and make it all shiny and new.
It's hard! (said in a my best whiny-teen voice.)
Hard or not, I'm not getting away from it anytime soon. The thing is, Once Upon a Time (2004) I wrote a book. It was my third novel-length manuscript and my first non-mystery novel attempt. Sparked by an idle question while reading an Anne Boleyn novel (What if Anne had not miscarried her son in January 1536?) and stoked by several eerie experiences at Hampton Court Palace and the Tower of London later that year, I began writing an alternate-history in which Anne Boleyn's son is born and becomes king of England upon Henry VIII's death.
Writing that book was exhilarating. I adored the puzzle play of fitting real people into a time period that almost but didn't quite exist (What would have become of George Boleyn if he wasn't executed for sleeping with his sister? What of the Duke of Norfolk and Mary Tudor in a world where she never comes to the throne? How does Elizabeth walk through a world of security and yet become the wary, intelligent woman who would become queen in her own turn?) and I also loved the freedom of my completely-fictional characters.
In fact, while writing that book, I distinctly remember thinking, "This is the book that's going to sell."
Only it didn't. Didn't even get me an agent, though it did generate the most interest I'd had to date. And when life and teenagers and grave illness intervened, I set it aside and moved on. I wrote a book about a contemporary girl who goes back in time to Napoleon's era and meets a British spy. I love that book. It got me an agent, the fabulous Tamar Rydzinski at Laura Dail Literary. I was giddy with excitement as it went on submission to eighteen editors.
Eighteen editors who all said no. Some of them said lots and lots of nice things, but in the end No was the operative word.
Not wanting to lose my fabulous agent, I sent her my alternate-history Boleyn book. She loved it. She loved it so much she called me up after reading it in less than a week and asked me to . . . wait for it . . .
Turn it into three books.
It took me eight months to create that first repurposed book, using approximately half of the original manuscript (leaving the other half to divide into a proposed books two and three.) That book went on submission one year ago. And on June 1, that book (along with the sort-of written books two and three) sold at auction to Ballantine.
Worth doing? Absolutely. Still hard? Undoubtedly.
Here are the top three difficulties I've encountered in repurposing a previous manuscript:
1. Being willing to add stuff. Lots and lots of stuff. I kind of thought I had a great plot line before. But four hundred pages of manuscript does not make three complete novels. So there are new characters, and new conflicts, and a new stand-alone arc for each novel. (At least, I assume there is, I'm still trying to figure out what book two's arc is. Shhhh, don't tell.) Weaving that into a previous story so that it's seamless takes a lot of patience and tinkering.
2. Being willing to cut stuff. This is really hard. I mean, I already have to write a bunch of new stuff, how can I possibly get rid of anything I've already got? But sometimes it has to go. Sometimes that scene with the great dialogue just isn't going to fit in the repurposed story. Sometimes entire pages need to go (like the one to two page interludes before each chapter written in Elizabeth Tudor's first-person POV--I love those pages, but that structure doesn't work anymore. Maybe they can go on my author website. As soon as I get one.)
3. Being fearless. I've heard lots of horror stories about second books. I'm finding them to be true. Middles have always been my weakness in a manuscript--they meander and sag and generally flounder about looking for a purpose. Now I'm writing an entire middle book, culled from the middle (read: weakest) section of my original manuscript and some days I'm convinced it will never come together. Which isn't really an option, considering the contract I signed. So I write awful paragraph after awful paragraph and just now, in this last week, have I had a glimmer here and there of something worth writing. So I fearlessly write crap and trust it will come together.
And hopefully, I'll learn enough that I can repurpose some other manuscripts. I still adore my first two mysteries . . . if I can just figure out how to take my great characters and write a plot worthy of them . . .