Step 1. Remove package-lock.json file if issue on npm install command for step 2.
step 2. Install NPM package by using the command . Path to this location c:\minify> npm install
step 3. To single file minification and showing output in console, run the comand c:\minify> node uglify.js 
step 4. To multiple file minification and showing output in console and output.min.js file , run the comand.
      Note that the file that need to be minify is mentioned in utlify*.js file