title: I can't install ruby 1.8.7
body: <p>I want to install ruby 1.8.7 and uninstall ruby 1.9.2 from main. Please don't suggest rvm as I do have that. But ruby 1.9.2p0 is sticked to my system.. I tried <code>sudo apt-get remove ruby</code>, it removes ruby, but when i run <code>ruby -v</code> it shows ruby 1.9.2p0 is there...
  I want to install ruby 1.8.7 for redmine.</p>
  
  <p>PLease suggest how to remove  1.9.2 and install 1.8.7</p>