Make Tech Easier published a tutorial about adding and removing Kexts from macOS.

How to Add and Remove Kexts from macOS

Kexts, or kernel extensions, expand the basic functionality of macOS’s Darwin kernel. They’re analogous to drivers under Windows, and they let the kernel communicate with your computer’s hardware. Most of the time, these files require no maintenance. But if you’re having problems, you may need to fiddle with a kext or two. In this article, you’ll learn how to add and remove Kexts on macOS. Do Macs on Big Sur and Later Use Kexts? Apple no longer recommends using kexts with your macOS device. 

How to Add and Remove Kexts from macOS