It seems to be quite simple "they" say....if you know how to compile on Linux (which I barely even know what that is ;)
If my memory serves I got some of it to work following this tutorial. And this was 2 months ago but I had some problems with it... I think it was something like I got WiFi to work, but then when I got to the Bluetooth part of the directions I wouldn't get that to work in addition to the WiFi (or the WiFi bricked the bluetooth or vice versus....I just gave up - it's NOT worth it to me to spend like 10+ hours on something everybody is telling me is already baked into the software (and/or how it's "so easy" to compile the drivers yourself...). Still have the dongle gathering dust though...
Regardless, all this is kinda pointless for the Zero's now that the W (wireless and Bluetooth) model came out - and cheaper to just buy that instead of this combo dongle.