Delete/Combine Pages

So, one of the two equal manga series will be deleted (maybe this one, with less info), and the volume it has be manually re-created on the one that will live (the one with the colon in the name?)? Or can books be re-associated to another series? If not, the book will have to be deleted, too, I suppose, if it doesn't die with the series. (Unless I'm totally misunderstanding something. ^_^;)

EDIT: I added the second book to the the first manga series linked above, so they are together now. (I used the same name it had...) I guess the other one can be deleted. Sorry if I shouldn't have done that. ^_^;