$ sudo apt-get remove libdm0 

Uninstall libdm0 including dependent package

If you would like to remove libdm0 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libdm0 

Use Purging libdm0

If you use with purge options to libdm0 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libdm0 

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 libdm0 

See Also,