1. Download Super-Root.apk for Lenovo K900 from this link : http://sh.st/jkq52
Tutorial Video : Easy Way To Download Super-Root.apk = http://sh.st/jkweO
2. Connect your device to your PC using the USB cable.
3. Copy the Super-Root.apk over to the root of your SD card.
4. Once it’s been copied, disconnect your device from your PC.
5. Head to Menu>>Settings>>Security on your device and enable
