Install and launch the program on your computer, and connect your device to the computer with a USB cable or via Wi-Fi.
When Android device is successfully connected, you will see the interface appearing on your computer with all data presenting on it. If no, you need to enable USB debugging on your Android in advance.
Tab "Contacts" - "All Contacts" and it shifts to the contact managing window. Now, click "Import" button, you can select the CSV contact files that you want to import to your Android.
The creator of this guide has not included tools