Previously I navigated to /etc/lightdm/lightdm.conf and changed user-session=ubuntu. lightdm.conf doesn't exist in Ubuntu 14.04 at that location, so how do I change user-session=ubuntu to something else?
take a look in
I have Ubuntu 14.04 and Kubuntu installed. You can change environments from the login screen. Next to your username, where it asks for your password, click the small Ubuntu icon. It will open a drop-down menu, with your installed environments on it. Select your desired session from the drop-down menu, and login.