$ sudo apt-get remove libcext0 

Uninstall libcext0 including dependent package

If you would like to remove libcext0 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libcext0 

Use Purging libcext0

If you use with purge options to libcext0 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libcext0 

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 libcext0 

See Also,