Rotating a master page (body) from landscape to portrait

[Theresa de Valence]

Hello Framers,

I have a book which had files which were both portrait and landscape.
The document was formatted using MasterPageMaps reference page. Since
the majority of pages were landscape, the default lwft/right "body"
pages were landscape. 

I am stealing this document to use as the structure of a new book, but I
would like to change the default left/right body pages to be portrait. 

Could you advise how to rotate the master page left/right from landscape
to portrait? (I am using Frame 8 but the book was written in 7.2)

Theresa de Valence