$ sudo apt-get remove grap 

Uninstall grap including dependent package

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

$ sudo apt-get remove --auto-remove grap 

Use Purging grap

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

$ sudo apt-get purge grap 

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 grap 

See Also,