Can I reinstall BootCamp Assistant?

Hi, everyone.

I've been trying to install a cracked version of Windows 7 to a USB external hard drive through BootCamp Assistant. I found a YouTube video (this is the link: http://www.youtube.com/watch?v=vNyg3byolic ), the instructions of which I stupidly followed. The result of this has stopped BootCamp Assistant from opening at all.

Is there a way to delete, then reinstall BootCamp Assistant, as I don't want to edit any scripts that will wreck BootCamp even more.

Thanks!

SS2