How to Uninstall the Oka Mirror Audio Driver
1. Open Finder -> Press [command + shift + g], then input /Library/Audio/Plug-Ins/HAL/
2. Delete the "Oka Mirror Audio Driver.driver"
3. Reboot the system, then the driver is gone.
If you are a programmer and you do not want to reboot, you can also input "sudo launchctl kickstart -kp system/com.apple.audio.coreaudiod" in a terminal app.
If you want to install the driver again, you can read How to install Oka Mirror Audio Driver to learn how to install it.