$ sudo apt-get remove gammu-smsd 

Uninstall gammu-smsd including dependent package

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

$ sudo apt-get remove --auto-remove gammu-smsd 

Use Purging gammu-smsd

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

$ sudo apt-get purge gammu-smsd 

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 gammu-smsd 

See Also,