You can uninstall or removes an installed gnupg-curl package itself from Ubuntu 12.04 LTS (Precise Pangolin) through the terminal,
$ sudo apt-get remove gnupg-curl
If you would like to remove gnupg-curl and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove gnupg-curl
If you use with purge options to gnupg-curl package all the configuration and dependent packages will be removed.
$ sudo apt-get purge gnupg-curl
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 gnupg-curl