you can install kexts files (example.kext) with Kext Helper b7 (google it).

Find the kexts manualy (for example try netkas site for video driver, try to use nvidia injector), and install it.

If the system cant't boot up, try -x argument on boot options to start the OS in safe mode, and then disable the driver.

Drivers are located in /system/library/extensions. Before replace a driver with kex helper, backup the old one (if exist). just go to extension directory and copy the old one. Then install the new one with the kext helper.