A family of Microsoft word processing software products for creating web, email, and print documents.
Just as with deleting any other type of file, you need to navigate in Finder to the location where they are saved. Assuming you have not modified the default File Location in Word Preferences, the default location for User Templates in Word 2016 is:
~:Home:Library:Group Containers:UBF8T346G9.Office:User Content:Templates
To get into the correct Library folder, go into Finder then hold the Option key while you open the Go menu. You should see Library listed directly beneath Home.