volume down fix mainboard broke

I have a gsm galaxy nexus which one friend broke the volume flex, he buy a replacement part but wile it arrive, he detach the Brocken flex by pulling it out instead desoldering the part, now I want to solder the new flex but the golden point of the volume down to join the flex and the bainboard is missing because he pull out the old flex,

how can I get it work again, or where I can soldering the flex to fix the volume down button

Sorry my bad english im from mexico