title: Why I don't have permissions to remove six while installing a pip package?
body: <p>I've run this command to pip install TensorFlow:</p>
  
  <pre><code>pip install https://storage.googleapis.com/tensorflow/linux/cpu/tensorflow-0.5.0-cp27-none-linux_x86_64.whl
  </code></pre>
  
  <p>But I'm having trouble removing six (to reinstall it anyway?)</p>
  
  <p>Does anyone have any insight into this problem. <code>pip uninstall six</code> doesn't work either</p>
  
  <p>my terminal is spitting out:</p>
  
  <pre><code>Collecting tensorflow==0.5.0 from https://storage.googleapis.com/tensorflow/linux/cpu/tensorflow-0.5.0-cp27-none-linux_x86_64.whl
    Using cached https://storage.googleapis.com/tensorflow/linux/cpu/tensorflow-0.5.0-cp27-none-linux_x86_64.whl
  Collecting six&gt;=1.10.0 (from tensorflow==0.5.0)
    Using cached six-1.10.0-py2.py3-none-any.whl
  Collecting numpy&gt;=1.9.2 (from tensorflow==0.5.0)
  Installing collected packages: six, numpy, tensorflow
    Found existing installation: six 1.9.0
      Uninstalling six-1.9.0:
  Exception:
  Traceback (most recent call last):
    File "/usr/local/lib/python2.7/site-packages/pip/basecommand.py", line 211, in main
      status = self.run(options, args)
    File "/usr/local/lib/python2.7/site-packages/pip/commands/install.py", line 311, in run
      root=options.root_path,
    File "/usr/local/lib/python2.7/site-packages/pip/req/req_set.py", line 640, in install
      requirement.uninstall(auto_confirm=True)
    File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 716, in uninstall
      paths_to_remove.remove(auto_confirm)
    File "/usr/local/lib/python2.7/site-packages/pip/req/req_uninstall.py", line 125, in remove
      renames(path, new_path)
    File "/usr/local/lib/python2.7/site-packages/pip/utils/__init__.py", line 315, in renames
      shutil.move(old, new)
    File "/usr/local/lib/python2.7/shutil.py", line 303, in move
      os.unlink(src)
  OSError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/site-packages/six-1.9.0.dist-info/DESCRIPTION.rst'
  </code></pre>