First off, I was not the one who figured this out. It was done by a guy on the RV forum. You can go to the link below for details on what connectors to buy and how to wire them. I know nothing about electronics so I was shocked when I was actually able to get this to work. My total cost to make this cable was about $10 and one hours worth of my time.
Basically you just need two special connectors and a cable. I ended up using speaker wire for the cable.
For those who aren't familiar with the GoPro camera, it does not come with a LED view screen (though you can buy a "back-pak" separately that will do this). You can't see exactly what you are shooting or the framing for the video. Being able to set up the camera by viewing the video thru the IFly is a big help.
The IFly also displays the recording icon AND the recording time so you know for sure it is recording and how much longer you may have left. Also the IFly not only shows the video, but it also displays the settings menu from the GoPro making it easier to read for us old farts.
Honestly I didn't believe this would work because there were some comments made that the GoPro was a "digital signal" and the IFly had an "analogue" something or other. Anyway, it definitely does work.
For details on making the cable go here:
http://www.vansairforce.com/community/showthread.php?t=81905
I ordered the plugs from Mouser as was suggested (they are $2 to $3 each). Rod points out on his directions to use a narrow tipped solder iron and small rosin core solder, both of which I happened to have. Soldering was a challenge because the connections are so small. I pre-soldered the wire and use electrical tape to help hold things in place while I soldered.
If you have a GoPro I can't imagine not spending a few dollars and putting together this cable.
Gary