$ sudo apt-get remove libg20 

Uninstall libg20 including dependent package

If you would like to remove libg20 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libg20 

Use Purging libg20

If you use with purge options to libg20 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libg20 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove libg20 

See Also,