@chowtang the micro USB port is soldered to your board. You will have to disassemble your phone, desolder the old port and then resolder a new port. Replacement parts are readily available at many online stores. To replace the port and since iFixit does not yet have a guide for this, use something like [https://www.youtube.com/watch?v=UMoeshuokaw|like this video] for the disassembly and [https://www.youtube.com/watch?v=rUoip_dXFUE|this video] for the repair.
While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.
Repair is War on Entropy!