$ sudo apt-get remove libjmagick6-jni 

Uninstall libjmagick6-jni including dependent package

If you would like to remove libjmagick6-jni and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libjmagick6-jni 

Use Purging libjmagick6-jni

If you use with purge options to libjmagick6-jni package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libjmagick6-jni 

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 libjmagick6-jni 

See Also,