$ sudo apt-get remove opj2dat 

Uninstall opj2dat including dependent package

If you would like to remove opj2dat and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove opj2dat 

Use Purging opj2dat

If you use with purge options to opj2dat package all the configuration and dependent packages will be removed.

$ sudo apt-get purge opj2dat 

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 opj2dat 

See Also,