You can uninstall or removes an installed nemo package itself from Ubuntu 14.04 LTS (Trusty Tahr) through the terminal,
$ sudo apt-get remove nemo
If you would like to remove nemo and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove nemo
If you use with purge options to nemo package all the configuration and dependent packages will be removed.
$ sudo apt-get purge nemo
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 nemo