Goodreads Librarians Group discussion

I own one copy of Ana de las Tejas Verdes (Anne of Green Gables) which is the first book in the series of Anne of Green Gables by Lucy Maud Montgomery. My copy's ISBN is 978-84-1393-229-3 being the original title "Anne of Green Gables" but someone changed it to "Anne of the Island" (which is the third book in the series), and I don't know how to changed it without messing up everything. Please help!

Done. All you had to do was edit the original title field.
This does not involve adding new books.