You can't use Yank to uninstall Yank. However, Yank has it's own built-in Uninstall command. If you ever want to uninstall Yank, or if you want to re-start Yank with new settings, simply choose Uninstall Yank... from the Yank File menu. Uninstalling Yank will move all its preference and support files to the trash. You can finish uninstalling Yank by then quitting it and throwing the application file in the trash.
If you decide to uninstall Yank, we would appreciate it if you could take a moment to write to us and tell us why you decided not to use Yank.