Reaver has been designed to be a robust and practical attack against WPS, and has been tested against a wide variety of access points and WPS implementations.
On average Reaver will recover the target AP's plain text WPA/WPA2 passphrase in 4-10 hours, depending on the AP. In practice, it will generally take half this time to guess the correct WPS pin and recover the passphrase.
Step 1 :
sudo apt-get install subversion build-essential libpcap0.8-dev libpcap-dev
svn checkout http://reaver-wps.googlecode.com/svn/trunk/ reaver
Step 2 :
To run it. You can run it at any directory.
That's all! See you.