In iOS, here are the steps for upgrading the firmware.
Step 1. Go to the Devices page. There should be a red triangle indicating a new firmware is available.
Click on Firmware Version. Make sure you are connected to the internet before you begin an firmware upgrade. This is necessary because the new firmware files are located at our servers.
Step 2. It will prompt you on whether you would like to perform a firmware upgrade. Click upgrade to perform the upgrade.
Step 3. The download process will commence. Once it finished download, it will start the install and show a percentage progress. If it gets stuck, you may tap the screen to cancel the process.
Step 4. When upgrade is completed. You will see the following screen. Tap it to return to the Device Screen.
Step 5. In the settings page, the device name will be temporarily changed to DfuTarg. Select it to connect. If you go to Home and come back to the Device page, your original device name will appear. 
Step 6. Please perform the calibration of the device again. For details of how to perform the calibration please refer to the FAQ.
It is also recommended to clear the Flash Memory at this time. Just click on Memory Usage and select "Clear Memory"