The way to solder the usb port if it has worked loose but still in place is to have a third hand or someone help you put some slight pressure in the centre top of the shield surrounding the port while you use a very slim long round tip soldering iron that does not have to be too hot just hot enough to melt the solder on the pins, keep the pressure applied and work fast touching all the legs at the rear of the port back and forward until they re-solder themselves into place and the port is sitting flat as it was beforehand, once you have done this you can apply solder in a minute form to each leg to finish the job.

Before putting it all back together check you have no shorts and if you can follow the picture you will see where each pin of the port goes to, if you check continuity from the legs of the port to the components they are linked too without any problems then your done, put it all back together and test.

The latter is also a testing procedure to find out if your port is attached or not as it is often the case the break can not be seen, remember we are dealing with through hole here and not tracks running out from the usb port itself.

The easiest and safest way to cure a detached port of one or more pins that do not make after the soldering attempt is to wire from pin to the component and you will have to follow wiring diagrams and pics that have been posted on here by some very helpful members.