Empty root trash with BleachBit
Sometimes, you might browse your files as root and delete things. Unfortunately that creates a problem, how to empty root’s trash bin. It’s not so easy. Here’s one way. Use Bleachbit (available on repository) this app is your computer janitor. If you don’t have it installed, open a terminal and:
sudo apt-get install bleachbit
Alternatively you can use synaptic or the software center.
After installation there are be two launchers in System Tools: one opens bleachbit as root and one as ordinary user.
Choose the Bleachbit (as Root) and then if you want to delete root’s Trash, check the Trash option. Click Preview to see what files are to be deleted and how much disk space will be recovered.
The first time I did this there were over 2 gigabytes of files in my root trash. That’s about 15% of my root filesystem, so it was well worth doing.