So, you just self-published your novel after spending weeks (or months) carefully combing over it to make sure it contained no typos.
Your friend takes you out to celebrate, and in between drinks, she takes out her phone to show you a couple of typos she highlighted.
“It’s no big deal,” she assures you. “I barely caught them myself, and it’s an ebook, so you can fix it quickly.”
You stare at her like a deer caught in the headlights. You have no idea how to edit your already published work.
Well, here’s how I did it on my mac for my novel, Desert Rhapsody. You’ll need these programs:
1. Sigil.
3. Calibre.
4. Kindle for Mac.
For .ePub files:
1. Locate your .ePub file: if you don’t have it, or if you lost it, just download it from the website you published it on. I published on smashwords, so I downloaded it from there.
2. Open Sigil, and then your .ePub file (Go to file-open).
3. Edit the book using Sigil (the program is pretty much self-explanatory).
4. Save your revised work, by clicking file-save, or file-save as (if you don’t want to overwrite the original .ePub file).
5. Open the ebook on Adobe Digital Editions to check if your work was saved correctly or to see if the book in general is acting normally.
6. Go to the website you uploaded the book on and upload the new version: for smashwords, go to Dashboard then “Upload new version” (under “Operations”).
For .mobi files:
1. Locate your .mobi file: I couldn’t download it from amazon. The version they have is not .mobi and it’s locked (i.e. you can’t edit it).
2. Open Calibre and convert your .mobi file to .epub: Simple enough. Select the book, then click on “convert individually” under the “convert books” button. In the window that pops up there is an “input format” and “output format” on the top-left and top-right corners respectively.
3. Edit the new .ePub file using Sigil (the aforementioned steps 2-4) then check if it is correct using Adobe Digital Editions (step 5 previously).
4. Use Calibre to turn the revised .ePub file back into .mobi. Just reverse the input and output format on calibre.
5. Open the .mobi file on kindle to see if everything is running smoothly.
6. Go to your KDP page, select your book, then select “edit book details” under “actions”. Upload the revised .mobi file just as you uploaded the original.
And that’s how I did it. Simple.
Hope this helped.
* Update: You can actually upload an epub file directly to KDP without converting it to mobi, so step 4 is moot. As for step 1 for mobi files, you can locate your mobi file after clicking on your book on your bookshelf KDP page, then scroll down to the bottom of the page and click on “Download Book Preview File.” This file will be an unlocked mobi file. Cheerios.
Ameen Basheh 
Thank you so much for these instructions. They were clear and were a huge boost of confidence for me while I corrected those minor nagging items in my ebook that somehow slipped through.
No problem. I’m glad they helped 🙂