This tutorial will explain how to change Screen resolution in Ubuntu and this might work in all ubuntu versions
Procedure to follow
1) Go to System ---> Preferences ---> Display
2) Once it opens you should see similar to the following screen here you can mirroring screens, detecting monitors, refresh rate, resolution, rotation, and to show the panel icon.
3) If you choose to display the panel icon option in the above screen you should see similar to the following screen in your notification area from here you can configure screen resolution