Not impossible just very hard, I have done quite a few of these mini USB's for Tomtom and the likes, I would say as with what Laffindude says just put quite a lot of flux on, also may be worth looking into a new jack with longer pins and or a very fine soldering tip, if all else fails you could always take it to someone who deals with electronics it would be a simple problem as long as no tracks are missing and the earths are not damaged.