My son dropped my wife's Iphone on flagstones...
Needless to say cracked screen.
2 hr. repair step by step instructions were perfect. I found using the magnetic project mat to label the length of screws and certain parts to be a big help!
Use the repair guides and take your time. Not a job for a beginner but very rewarding!
Magnetic Project Mat
iPhone 4 (GSM/AT&T) Headphone Jack & Volume Control Cable