Help changing colors

I would like some assistance editing this logo template I received. Having problems changing the green gradiant to a color of my choice. I am novice with photoshop.

How do I do this without effecting the other part of the logo? They designer only used one layer for the logo and a layer for the text.

See link:

http://www.steadyscene.com/pwi/4018.zip (141kb)

Thanks!

Daniel