How to clean iphone 4 inside (front) camera?

My iphone 4 screen cracked and it apears to be some residue from the glass on my camera. I took some of the glass off to reveal the camera and it seems like its all over and around. The picture quality is bad now and i need to know what i can use to possibly clean it without damaging it

The larger lens of the iPhone 4 and 4S camera is still teeny. The actual lens itself is protected by an external lens casing. While the lens casing is about 5 mm, the lens itself is about than 2 mm - just a little larger than the head of a pin. Even a small smudge or a fingerprint on your lens can really effect the quality of your images. Also, the iPhone 4S' lens casing is no longer recessed as in previous iPhones.It's pretty much flush with the back of the phones case, making it even easier to get smudged and dirty. Fortunately, keeping the iPhone 4S' lens clean is even easier than previous models.

The flush lens casing is both good and bad.It's bad in that it's easier to accidentally smudge and get fingerprints.It's much better, though, because it's incredibly easy to clean. It also seems to be sturdier than previous lens casings.