Getting Netgear WNA3100 to work, Linux Headers required

I started on my Volumio project yesterday, and so far, so good. But Now I’m trying to get Wifi to work… And all I have is one of those @#&$%!! Netgear WNA3100 USB network adapters with one of those @#&$%!! Broadcom chipsets…

Ok, not really a big deal, so far I’ve got it to work on pretty much all my Linux-based systems using ndiswrapper. But on this Volumio system, I can’t use it due to the linux headers for the kernel version (3.18.25) are not available from the repository. And without them, installing ndiswrapper from the repository throws an error and compiling it from scratch isn’t going to work either.

I tried to find the headers on the internet and do a manual install, but I suck at those things and kinda screwed up my Volumio in the process. No worries though, writing the Volumio image to my systems’ SSD again doesn’t take very long :stuck_out_tongue:

So… How can I get the Linux headers installed?