At first I thought this was one of the plug in type motherboard connectors and was easy to get to...seems you'll need to take the motherboard out, desolder the old jack and replace it. If its just a case of cracked solder on the feet of the jack you may just be able to reheat the existing solder to stabilize the jack. I used a heat gun on similar repairs as it gets all the pins/feet loose at the same time, you just need to protect the surrounding components from the heat. A quick google shows several on line disassembly manuals and youtube videos that would help, or you can click on the guides to the right under the picture.