That's a massive umbrella! I've never owned one, but It would be amazing if you could stretch a big piece of translucent white cloth over it and create an enormous octobox! The light coming out of it would be ridiculously soft and beautiful. Should do the job you ask of it no problem (as-is). What are you using to flash off of it?
Mark
EDIT: I would like to add, though, that if it's the silver/black one, and not the white/black one, the shadows produced if the umbrella's light is hitting the subject could be quite strong. The reflective version, well, both versions really, are designed by their parabolic nature to shoot the light back in a more column-like fashion than a soft, wide-spread fashion. Keep this in mind and watch the shadows produced. They may be more of a hassle than getting rid of them are..