$ sudo apt-get remove ri1.9.1 

Uninstall ri1.9.1 including dependent package

If you would like to remove ri1.9.1 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove ri1.9.1 

Use Purging ri1.9.1

If you use with purge options to ri1.9.1 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge ri1.9.1 

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 ri1.9.1 

See Also,