This could be hard, it's not likely to be easy. The simpler the manuscript format, the easier this will be.
I may be giving you more than you need, but maybe the documentation folks can make use of this in some way too.
- Dennis
1. FINAL SHOWING MARKUP
"Final Showing Markup" is a Track Changes option in Microsoft Office. (The other options are Original, Original Showing Markup, and Final). Final Showing Markup appears to be the default setting. "Final Showing Markup" shows how the document will appear when all changes are accepted, and what the changes are that leave it in that shape. This option has been available in all versions of Microsoft Word *since* Office 2000.
What that means, when using Word, is that insertions are marked by underlining but that deletions don't show in the text. Instead, deletion points are linked to balloons in the margin that show what was deleted. (In case you were wondering, Original Showing Markup has the insertions in marginal balloons and deletions are strikeouts in the text.)
There is a description of this at
<http://www.shaunakelly.com/word/sharing/howtousethereviewingtoolbar.html>.
2. IN-LINE ONLY CHANGES - ALL THAT LIBREOFFICE HAS
In Microsoft Office, there is also a kind of tracked-changes presentation where both insertions (colored and underlined usually) and deletions (different color, with strikethrough usually) are all in the running text. This is accomplished by turning off the balloon feature.
In Libre Office, this is the *only* way that tracked changes can be shown. If you look at Tools | Options | LibreOffice Writer | Changes you will see what is under your control.
3. THE GOOD NEWS
3.1 If, with the final draft you are being asked to review, set the Changes options to something your editor is asking to see, such as Insertions Underlined and in Light Blue color. Deletions with Strikethrough and Red color. Changed attributes Underlined Double and Color Magenta 4 or so. I don't know if he wants to see change marks, but you can leave them on the left margin and black.
3.2 IN FACT, these setting apply to the software being used to view the document. The settings don't travel with the document. A reviewer will see their settings applied as if that is what you used. You do have to turn on Record and Show in the Edit | Changes ... menu though.
3.3 IF YOU ARE LUCKY, your editor will open the document for Review with Final Showing Markup and will see exactly what is being expected. You might warn the editor that the setting might have to be selected after opening the document in Word.
4. THE BAD NEWS
4.1 I don't know if you have been turning back change-marked documents, or receiving change-marked documents. If you have, you probably know how careful you have to be.
4.2 To put it politely, interoperability of change-tracking across formats is not terrific. Extensive changes and rearrangements can be messed up something also when there is a conversion between formats.
4.3 CAREFUL, SMALL STEPS SHOULD WORK. I assume your manuscript is not complex. So long as you are down to correcting typos and short wordings, you should be fine. Instead of making a change between two paragraphs or across other mixes of materials (list items, text flowing across images, table rows), keep the changes small. Make multiple small changes, rather than big ones that span units of text. This works best if your document is not done against an exotic template and has rich features as well as text.
4.4 CONFIRM IF YOU CAN. If you have a Word viewer, you might be able to see if the change-tracking goes across all right. If saving as .doc and then reopening it in LibreOffice looks fine, you are probably all right too. (But you might still be all right but unable to confirm it if round trip to .doc and back into LibreOffice deviates in some way.)