You cannot. Styles are at the heart of how Word formats documents. Any Word document will have Styles, whether or not they are used.

What is it you are trying to accomplish by doing this? Perhaps that can be done, just not with this method.

If you are going to be using Word much at all, you owe it to yourself to spend some time learning how to use Styles. Otherwise, it will feel as if the computer is trying to sabotage your work.

Understanding Styles in Microsoft Word
Tips for Understanding Styles in Word by Shauna Kelly