Photo Rendering Help

[Texas Fan]

So my boss wants me to print out a huge sign of our logo. Problem is he created it i think in paint, and when i blow it up it looks horrible. How can I fix this to be able to print it, and i also want to see about removing some of the black around the logo also. You can also see the logo on elitelandservices.com at the top of the page. Maybe if I could get the colors kind flipped, like the white lettering to black and the black areas to white would be cool also. Let me know what yall think.

Thanks