The first step is to get the library that will handle the REST calls, which is called aREST. It is hosted on GitHub and you can visit the page at the following link:
To install the library, first open up the Arduino library manager
Search for the aREST library and install it
We also have a great tutorial on Arduino library installation at:
http://learn.adafruit.com/adafruit-all-about-arduino-libraries-install-use
