I can promote or demote a single heading using Navigator, but it doesn’t have an option to select multiple or all headings for promotion. Is there a quick way to get them all promoted?
Do you want, that the heading which has style “heading 1” keeps this style, or should it have the style “heading 2” afterwards?
If you will do that really for all headings, then you can use the Find & Replace dialog from menu Edit. Expand the dialog with button other optionsand enable the option Search for Paragraph styles.
If you will keep the paragraphs, which have currently got style “heading 1”, different, then you can assign a new style to them, for example “title”. Select “heading 1” in the search field and “title” in the replace field. Replace all. That would remove them from the navigator unless you adapt the settings in the outline numbering dialog.
Next select “heading 2” in the search field and “heading 1” in the replace field. Replace all.
Next select “heading 3” in the search field and “heading 2” in the replace field. Replace all.
and so on for all style you want to promote.