I coauthored a book that I originally came up with and wrote all of the chapters for. We initially agreed to split the profits 50-50 but after realizing that it was all of my ideas and all of my efforts to market I reduced it to a 70-30 split. We did not have an official agreement, which I know I messed up on.
I want to update the book but need to know the best approach-I have several chapters to add. Should I do a second edition with the updated information or rename it so I can just include my name?