You can uninstall or removes an installed iio-sensor-proxy package itself from Ubuntu 17.04 (Zesty Zapus) through the terminal,
$ sudo apt-get remove iio-sensor-proxy
If you would like to remove iio-sensor-proxy and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove iio-sensor-proxy
If you use with purge options to iio-sensor-proxy package all the configuration and dependent packages will be removed.
$ sudo apt-get purge iio-sensor-proxy
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 iio-sensor-proxy