In order to remove this application from your computer, you can try to use the Uninstaller from Control Panel. To do that, you need to go to Start -> Control Panel -> Add/Remove Programs (Windows XP) or Programs and Features (Windows 7) select the software and hit Uninstall. If you can't complete the process by this way, you can try using a third party tool like Revo Uninstaller. This tool is specially designed to force any application to uninstall. Also, it is advised to use AdwCleaner to make sure that there are no leftover rogue registry keys or toolbars in your system.
This software needs to be removed from your browser also. Depending on the browser that you use, this can be done differently. You can use Google to find a solution for your browser. For Internet Explorer, you need to open the browser, click on the Option button -> Manage add-ons, search for the LyricsSay add-on and remove it.