To change the dock connector on an iphone 4 or 4s it doesn't take long , it take a measly 45 minutes a few screw drivers like a torx 1-4 a flat head a philips the new dock connector and tweezers
in this link (HERE) there is the short cut to the page with the links to my youtube videos that show the detailed guide of the full disasembly and reasemble to put the new part in
