Tal Ben Ami,
Sorry to say that surface pro 3 is hard to open to do the repairs. Good news is USB port replaceable easily because of surface pro3 comes with full size USB port. if the USB connector internally damaged you can replace it. if you cannot find damages on it check the 5V DC power rails + USB fuse before replacing the USB port. This [guide|26595|guid] will help you to teardown surface P3, use hot air around 200C air 20 (Hakko) to heat the glued canners and it will help you to open the device without damages.
Cheers!