I. 1. Open a terminal 2. type: kextunload /System/Library/Extensions/osx-pl2303.kext/ 3. The command prompt will ask for your administrator password 4. type: sudo rm -r /System/Library/Extensions/osx-pl2303.kext/ 5. The command prompt will ask for your administrator password 6. type: sudo rm -r /Library/Receipts/osx-pl2303.pkg/ The driver should be uninstalled.
II. 1. Open a terminal 2. Type: cd/System/Library/Extensions/ 3. Type: SUDO rm -r UC-232AC.kext/ 4. Punch in the password when prompted 5. Restart your Mac
Note: If above 2 methods don't work, please contact ATEN Tech Support
For details, please refer to the below video.