You can uninstall or removes an installed libgles2-nvidia package itself from Debian 8 (Jessie) through the terminal,
$ sudo apt-get remove libgles2-nvidia
If you would like to remove libgles2-nvidia and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove libgles2-nvidia
If you use with purge options to libgles2-nvidia package all the configuration and dependent packages will be removed.
$ sudo apt-get purge libgles2-nvidia
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 libgles2-nvidia