are you saying the little piece of plastic with the four wires inside the rectangular box has broken off? or that the whole box itself?
either way, if you have all the parts, you could technicaly fix it yourself with a little crazy glue, and a soldering iron. if you laptop is under warranty i would highly suggest you talk to the manufacturer first, you could get it fixed for free or at least really cheap. otherwise, you would just have to crack open the thing yourself, and have at it. but do it with extreme sensitivity, and if you can find one for your model, use a generic repair guide/schematic for you laptop.
i dont think you will find much info out there specifically on this problem. i myself come across all the problems that have never happened before so i know what its like.
about the fixing: besides the metal box, there is only the four connectors on the plasic tab. now you could just technially glue the plastic tab back on, and solder the four connections. but it would be hard to do, seeing the dimesions of your work area inside the usb port.
so to sum things up:
1 further survey the problem (magnifying lens needed)
2 contact your manufacturer
3 look for an online guide/schematic for the parts inside your laptop.