I don't know how your document is set up and if pages are added if overflow text is available.
If your text is linked, go first into one of the frames with the text curser, select all. Then go through select all with the selection tool and press delete.
If your frames are not linked, select all on each page with the selection tool and delete.
If your frames come from the master, delete them on the master. Overrides (which should not be done on pages) you have to delete separately.