Upgrade Node.js and npm

Check your current Node.js and npm versions as follows:

$ node -v
v0.8.14
$ npm -v
1.1.65
$

Upgrade Node.js and npm by npm as follows:

$ sudo npm cache clean -f
$ sudo npm install -g n
$ sudo n stable
$

Check your upgraded Node.js and npm versions as follows:

$ node -v
v0.10.35
$ npm -v
1.4.28
$

Reference:
http://davidwalsh.name/upgrade-nodejs