Broken volume flex cable. How to fix?

So I did the unthinkable, I broke something a phone not soon after I got it. While I was changing the housing for the GNex, I forgot to remove the SIM card and it jammed the volume flex cable, and it ended up being severed.

I just ordered replacements parts on http://www.parts4repair.com/samsung-gala..., but I tried to find any help or information on how to reattach a new flex cable, however there seems to be no information.

iFixIt does say that the volume flex cable is soldered to the main board, but that's about it.

So my question is, how should I proceed to re-solder a new volume flex cable? I have some experience but I have never done something so "risky"... Am I better off finding a repair shop?