Question [Q] How to patch open source code to a kernel?

Situation:

I have a LG F260s/Optimus F7 and I would like to add fauxsound to the phone which enhances the audio quality, however, this following occurs to me. I know I need to get the kernel file and flash it, however, I do not know how to "add the source code" whatever it is being told in the picture. Thanks for any response.

What tools and procedure I need to enable that? The phone is already root and have busybox installed.
Attached Thumbnails
Click image for larger version

Name:	Screenshot_2014-04-11-23-12-36.png
Views:	286
Size:	95.2 KB
ID:	2680297