Moving Files from Sub-directory to Root directory

My ultimate goal is to move the files from a sub-directory to the root directory. I am currently doing a back-up of the wordpress site I built. One of the steps say I should removed the site files from the builder before copying the files from the sub-directory to the root-directory. I am not sure how to remove site files from the builder. I don't see in the instructions where it says to do that step.