Step 1 :
To install wpscan and her related packages.
sudo apt-get install git libcurl4-gnutls-dev libruby libxml2 libxml2-dev libxslt1-dev ruby1.9.1-dev
sudo -sH
cd /opt
git clone https://github.com/wpscanteam/wpscan.git
cd wpscan
sudo gem install bundler
sudo bundle install --without test developement
Step 2 :
To run it.
sudo -sH
cd /opt/wpscan
./wpscan.rb --url http://www.samiux.com
Step 3 :
To update it.
sudo -sH
cd /opt/wpscan
./wpscan.rb --update
That's all! See you.