Check out Video of Reassembling iPhone 4 of AT&T after iPhone 4 Repair Dock Connector
Well this is something very difficult and experts can do but for the first time in my life i have seen fixing hardware done by iMore team. The whole expert procedure has been posted and shared to the public on iMore portal but i was wondering who will take this bold step, if its iPhone 4 Dock connector goes out of order. So i probably call it Procedure for Experts only. So guys if you are not an hardware expert, please try it at your own risk.The Dock connector usually does not go out of order or it does not break that much easier but if you want to save some pennies or even dollars you can still try this out. All the parts are readily available in the mobile workshops or mobile whole market but one must have courage to perform.
If you decided to go with it you can follow the iMore Portal for Fixing iPhone 4 GSM Dock Connector and when you replace the broken on with the new one here is the video for the Reassembling iPhone 4 GSM