If the drivers are signed and released for Windows 8, then simply attach the device to your PC and use your INF or setup packages to install them. Alternatively, you will have to download the Driver Enforcement. This allows installation of unsigned drivers in Windows 8 and above.
To disable the feature press Windows + C > Change PC Settings > Update and Recovery > Recovery > Advanced Startup > Restart > Troubleshoot > Advanced options > Startup Settings > Restart.
Once you are at your desktop, install the drivers and accept the Warning message and then reboot and the device should work properly.