how to run gulp on project were is already instaled code example
Example 1: how to install gulp
npm install gulp-cli -g
Example 2: use gulp
npm init // create the package.json file
npm install -g gulp //If you haven't installed gulp globally before
npm install --save-dev gulp // --save-dev dependancy package.json
npm install --save-dev gulp-sass
npm install --save-dev gulp-print
your commands > gulpfile.js
gulp command