irregular spline

So, one of the setups that I run with is a dual-boot enabled MacBook Air with Kali Linux. Why, you may ask... Well no one really expects a Mac to be running anything other than OSX. So it catches people off guard if they really pay attention to what I'm doing. So far, I've come across only a few issues (like I can't get the internal Wi-Fi card to work, but I'm usually using an Alfa anyways). One such issue was that, upon running updates on the Kali side, grub pushed an update. Normally that's not an issue. However, if your setup is similar to mine, where rEFInd is being used from the OSX side....Well let's just say that grub overwrote rEFInd and now only shows the Kali startup. Now, I didn't really document how I got everything back to 'normal' (sorry, I'm out of luck now too if that happens again). But the basic steps were to bypass the grub boot, which allowed me to boot into the OSX partition, and re-install rEFInd. The question is, how do y