Comment 18 for bug 1425349

@mozit

i suppose you already know these commands:
- sudo apt-get clean
- sudo apt-get autoclean
- sudo apt-get autoremove
- sudo dpkg --configure -a

To clean a bit more, gtkorphan & bleachbit can also be used.

And for the record, questions are usually asked via ubuntuforums/askubuntu; learning via the many ubuntu's wiki/howto you can find around the buntu galaxy.