Go to the directory where MEP 14 is installed. Possibly, C:\Program Files\MAGIX\Movie_Edit_Pro_14_Plus (or something similar to that).
You should see a folder called "Data". Inside that, you should see "DVD" and then "Layout". Inside "Layout" I believe you will see the templates.
For example, open the "default" folder and you will see the default template files.
I have not tried deleting or installing any files in this folder structure, so you are on your own there. But that appears to be the location of the templates.