Where to fix shattered iphone 4 screen?

A friend of mine has an iphone 4 with a shattered screen and the apple store told her twice that they no longer do the screens, but my other friend has her iphone 4s screen repaired there. But she said I can have it if I know a place to get it fixed. I've seen some repair kits but I don't know if they work or if you have to know what you're doing. Is there anywhere to send it to get it fixed? Or anything like that?

Many people know, but some people don't know: search model name plus "repair guide" on any search enginge. They will show details about about part replacent etc. In detail. There are other websites that sell all the replacement parts, one of the bigger ones is http://portatronics.com (646) 797 2838. Then for the repair itself you can venture to do it yourself, or ask a friend who has done a similar repair before. This is the cheapest way to resolve this scenario.