You can uninstall or removes an installed m16c-flash package itself from Ubuntu 14.04 LTS (Trusty Tahr) through the terminal,
$ sudo apt-get remove m16c-flash
If you would like to remove m16c-flash and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove m16c-flash
If you use with purge options to m16c-flash package all the configuration and dependent packages will be removed.
$ sudo apt-get purge m16c-flash
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 m16c-flash