The idea of that word file is that it already contains the correct layout for an article. You only need to change the text and overwrite what is in the word file, except for the formatting. Whenever you add new section headings and the like, make sure to copy the style from the previous section headings. The layout file already contains examples for many elements of a manuscript, such as figures, equations, and the like. Again, if you want to use equations, figures, and so on, you just copy them from the layout example file to your file and just change the content, without changing the style.
When you are done with your article, you perform the final steps mentioned in the "abstract" of the template, which appears to contain concrete instructions for this step.
Note that in many of the better conferences, rejection of papers positively correlates with the paper being written in Word. So many authors would use LaTeX right from the start to not give the first impression that the paper is a rejection candidate (in addition to other reasons for using LaTeX). Of course, reviewers should not care about this, but there may be a subconscious bias against your contribution because of the correlation.