aux in is broken ,how can it be fixed

@boseman take a look at this guide. Step 6 shows the port soldered onto the board. So it would not be easy. You could try and purchase a broken Bose SoundLink Color and harvest the port from it. Or you could possibly pigtail a separate input port (cable) to it. This will depend on your soldering skills etc. If you can, post some images of the damage (disassembled) with your question. For that use this guide. That would allow us to see what you see and possibly point out where to solder to.