Open the Research Download or Upgrade Download tool. Click the Gear (Load Packet) icon and select the .pac file from your extracted firmware folder. Prepare the Phone:
This is the stock firmware required to reset the device.
The tool should show a progress bar once the connection is established.
Power off the phone and remove the battery for a few seconds. Reinsert the battery but do turn it on. Start Flashing: Click the Play/Start button in the tool.
The B310E uses a Spreadtrum (SPD) chipset, so you must use an SPD flash tool to load the firmware.