First remove the previously installed django 1.3.1 version by deleting the django folder inside /usr/local/lib/pythonx.x/dist-packages(x.x denotes the version of python).Then follow the below steps,

• Download Django 1.6 from here.




• Open the terminal and move to the directory where you placed the Django 1.6.

  
  
  

  cd path/to/driectory/which/contains/django1.6.tar.gz




• Extract the django1.6.tar.gz by running the below command.

  
  
  

  tar -xzvf Django-1.6.tar.gz




• Move to the Django-1.6 directory

  
  
  

  cd Django-1.6




• Run the below command to install Django-1.6

  
  
  

  sudo python setup.py install