You should be already connected to your Linux instance using SSH.
Following the official documentation of NodeJS, we would run the following command (This would add NodeJS distributions repositories):
$ curl --silent --location https://rpm.nodesource.com/setup_6.x | sudo bash -
The next and final step is to download and install:
$ sudo yum -y install nodejs
To ensure that node was installed correctly, use
node -v. Output should be similar:
$ node -v $ v6.11.2