two gold contact prongs under home button snapped

Whilst replacing the touch screen on my iphone3gs one of the two gold contact prongs(located directly under the home button) snapped! My home button now doesn't work and the only way to exit app's or anything is to totally power off the phone...frustrating! Can I completely replace the prongs? If so what is the part called? If not do you think soldering would work or risk damaging something else? Plz help any suggestion plz