1. Find, open, and edit normal.dot
In File Explorer, navigate to C:\Users\your-username\AppData\Roaming\Microsoft\Templates
Inside this folder, make a backup copy of Normal (select it with your left mouse click, press Ctrl + C, then Ctrl + V).
Next, double click on Normal
Edit the file as desired.
I edit the file’s paragraph styles, by ensuring Title, Header 1, Header 2 all have paragraph “after spacing” equal to paragraph “before spacing”.
To do this, I right click on the style (either Title, Header 1 etc.) in the Styles section of the Home tab, select Modify, choose Format at bottom left of the new window, choose Paragraph, and under Spacing, I ensure Before and After are the same (except for Title, where I leave Before at 0). I usually increase the spacing to 12 pt.
2. Apply the updated normal.dot to your document
Open the document that needs a new template attached.
Click the File tab.
On the File screen, choose the Options command.
The Word Options dialog box appears.
Choose Add-Ins from the left side of the Word Options dialog box.
Choose Templates from the Manage drop-down list.
You find the Manage drop-down list near the bottom of the dialog box.
Click the Go button.
The Templates and Add-ins dialog box appears. You should see which template is attached to the document, such as Normal.
Click the Attach button.
Word displays the Attach Template dialog box, which looks and works like the Open dialog box.
Select the template you want to attach.
The templates listed are stored on your computer, so you don’t see the full range of templates that you would find on the New screen.
Click the Open button.
The template is attached to your document.
Ensure that the option Automatically Update Document Styles is selected.
Updating styles means that your document’s current styles are changed to reflect those of the new template, which is probably what you want.
The styles stored in that template are now available to your document, and the document is now attached to the template.