You can use Amlogic USB Burning Tool to flash firmwares from a Windows PC to Android devices powered by Amlogic processors.
Download Amlogic USB Burning Tool v2.1.6 from here, here or here.
How to use Amlogic USB Burning Tool
1. Download Amlogic USB_Burning_Tool_v2.1.6 (8.56 MB).
2. Extract the archive and run setup_v2.1.6 file to install the tool.
3. Start the USB_Burning_Tool.
4. Click on File->Import image and select your specific .img firmware for your Amlogic device.
5. Make sure that your Amlogic device is powered off, with the USB OTG port connected to your PC. Use a toothpick to press the recovery button, and power the device. The USB burning tool should automatically detect your device.
6. Now click on the ‘Start’ button button to proceed with the firmware update which should last several minutes.