take the book you want to trade, and from the maintenance screen select export data.
choose 'export data into book' and then save that book as a seperate book. it will ask you if you want to make the book's contents secret. Unless you don't want that cepter to look in the book, select no.
go to the other cepter, have them go into the export data screen, then choose import data. Go to whatever mem card you saved it to, select it, then voila! they have their own copy of the book, though it does not add to their stock in any way and they can't edit it.