Currently, if you want to remove yourself as a chapter co-creator, you have to go to the work's Manage Chapters page, where you will find a "Remove Me As Author" button on any chapters you co-created.
That's both hard to find and confusingly-named, so we want to change it to "Remove Me As Chapter Co-Creator" and put a "Remove Me As Chapter Co-Creator" option on the Edit page for any chapters you co-created.
When you click the "Remove Me As Chapter Co-Creator" link, the confirmation pop-up should say, "Are you sure you want to remove yourself as a co-creator of this chapter?"
When you choose "OK" in the pop-up, you should get a blue flash message that says, "You have been removed as a creator from the chapter."
The chapter byline should also update.
Old information retained for record keeping:
Originally reported on Google Code with ID 1262
You should be able to post a new chapter that is just by you (i.e. remove
the co-author) when there is a co-author for earlier chapters in the work.
You should also be able to edit a chapter and remove another co-author
from a chapter.
(You shouldn't be able to do this for the whole work, just for individual
chapters in it.)