user14578: I am following a DIY guide that requires me to patch two arduino core library files: HID.cpp and USBAPI.h. This is not really practical for many reasons. I am not a native C programmer, but I am sure there are better ways to achieve the same without messing directly with system files. How can I override system library files without modifying the originals?

user368: Unfortunately there really isn't any way of doing that other than modifying those files. The good news is that it is perfectly viable to make the modifications under a different "core" and then amend boards.txt with the core containing the modifications.

14578: <p>I am following a DIY guide that requires me to patch two arduino core library files: <code>HID.cpp</code> and <code>USBAPI.h</code>. This is not really practical for many reasons. I am not a native C programmer, but I am sure there are better ways to achieve the same without messing directly with system files. How can I override system library files without modifying the originals?</p>
 368: <p>Unfortunately there <em>really</em> isn't any way of doing that other than modifying those files. The good news is that it is perfectly viable to make the modifications under a different "core" and then <a href="https://code.google.com/p/arduino/wiki/Platforms1" rel="nofollow">amend boards.txt</a> with the core containing the modifications.</p>
