How do I restore the original color scheme, icons, and theme?

view story

http://askubuntu.com – I'd like the original colour scheme, icon style of 12.04. I somehow lost the Ambiance theme (possible error or upgrade error). I re-installed 'light-themes' from the terminal and got it back. But the panel on the top that shows the options of sound, battery and wi-fi has changed and I can-not get the original setting back. In the windows, the close, minimize tools have shifted to the right instead of the original left side. I had installed MyUnity and Ubuntu Tweak but deleted them. As such, I want the original setting back. Kindly help me with the commands. I have searched for solutio (HowTos)