This is simply a matter of using the IncludeText field, almost as we did for composing the book earlier in this system. You may wish to compose your glossary using a separate MS Word Document and then simply cut and paste that file into the area under the Glossary heading.
The reason we are adding the Glossary after the Index has been created, is that you do not need the Index to locate words in the Glossary. An Index is a table of where those ideas can be found in the text. The Glossary ordering can be used by the reader to identify anything needed in the Glossary.