Resetting page numbers in a document after deleting them from a Book

Hello all!

I created a Book and added 2 documents to it. The page numbers changed properly to be continuously flowing.

I then decided to delete the second document from the Book. When I open it now, I see the page numbers still remain as if they were part of the book (67-87). I would like to revert them back to start at 1. How can I do this?

I cannot find this answer anywhere in the help area...

Thanks!