1. Connect the Samsung Galaxy S3 Mini to your computer using a USB cable.
2. Copy the CyanogenMod 11 custom ROM and Google Apps package then paste them to the SD card of your smartphone.
3. Disconnect the Galaxy S3 Mini then use the TWRP to reboot into recovery mode.
4. Use may touch commands to navigate and select throughout TWRP menu options.
5. Inside the recovery mode, select "backup" to save the current ROM on the phone. Use the "restore" if you want the saved ROM to be restored anytime.
6. Now perform a full wipe by selecting "wipe" on the menu to erase data, cache partition and Dalvik cache. CM users upgrading to version 11 can skip this step.
7. Install the CyanogenMod 11 by selecting "install" then search for the firmware you have pasted earlier. Apply the same with Google Apps package.
8. After the installation, select "reboot > system" to reboot the smartphone.
9. It may take at least 5 minutes to reach the home screen as the phone runs the new firmware for the first time.
Well done! Your Samsung Galaxy S3 Mini is now running the latest Android 4.4 KitKat thanks to CyanogenMod 11 custom ROM.