$ sudo apt-get remove grub-emu 

Uninstall grub-emu including dependent package

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

$ sudo apt-get remove --auto-remove grub-emu 

Use Purging grub-emu

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

$ sudo apt-get purge grub-emu 

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 grub-emu 

See Also,