There are a few way's to install WebSocket's to your project. Here are some example's:

npm install --save ws

or inside your package.json using:

"dependencies": {
  "ws": "*"
},

To add ws to your file's simply use:

var ws = require('ws');

To open a new WebSocket, simply add something like:

var WebSocket = require("ws");
var ws = new WebSocket("ws://host:8080/OptionalPathName);
// Continue on with your code...

Or to open a server, use:

var WebSocketServer = require("ws").Server;
var ws = new WebSocketServer({port: 8080, path: "OptionalPathName"});

var WebSocketServer = require('ws').Server
, wss = new WebSocketServer({ port: 8080 }); // If you want to add a path as well, use path: "PathName"

wss.on('connection', function connection(ws) {
  ws.on('message', function incoming(message) {
    console.log('received: %s', message);
  });

  ws.send('something');
});