$ sudo apt-get remove r8168-dkms 

Uninstall r8168-dkms including dependent package

If you would like to remove r8168-dkms and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove r8168-dkms 

Use Purging r8168-dkms

If you use with purge options to r8168-dkms package all the configuration and dependent packages will be removed.

$ sudo apt-get purge r8168-dkms 

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 r8168-dkms 

See Also,