Selecting a number of headings

[BML]

I have been writing a document for a number of years and every so often I make a mistake such as today when I found that the document was a read only one. My way of dealing with that was to select it all and paste it to a new page but I then found that although my paragraph headings remained on the document they had disappeared from the column on the left of the document headed, "Navigation".
Is there any way that I could select all of those headings on the document in one go and click onto "Headings 1" from styles thereby moving them back to the column on the left of the document thereby saving me having to select each paragraph heading individually and go through the process of copying them one at a time.

 

[Tim Locke]

If this is Word then perhaps you might get a quicker reply on a Word Forum. I bet most Word users ( me for instance) haven't generated a big complex document for years if ever.