$ sudo apt-get remove coturn 

Uninstall coturn including dependent package

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

$ sudo apt-get remove --auto-remove coturn 

Use Purging coturn

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

$ sudo apt-get purge coturn 

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 coturn 

See Also,