gulp 3.9.1 to gulp 4 code example

Example: how to install gulp version 3.9.1

I am answering my own question, just so it is useful for others.

Is there a way to remove the global gulp version, but keep the project specific gulp?
No. AFAIK, you are required to install gulp globally as well as one specific to your project.

More info on gulp versions here.

Why do we need to install gulp globally and locally?
http://blog.dwaynecrooks.com/post/110903139442/why-do-we-need-to-install-gulp-globally-and
https://github.com/gulpjs/gulp/issues/171
https://github.com/gulpjs/gulp/issues/140
Or can I update my global version gulp to @3.8.11?
Since I was facing a mismatch in my local version, I had to update it from the project folder itself.

npm install [email protected] --save
More info on this here.

http://www.eskocruz.com/gulp-version-mismatch