Step 1: Download the stock ROM zip file given above and extract it on your computer. You will         find SP FlashTool   and Android scatter file after extracting.

Step 2: Now download  or install Driver on your computer. In case if you have already installed USB driver on your computer skip this step

Step 3: Next, switch off your HTC Desire 820G Plus Dual SIM smartphone and remove the battery (it is removable).

Step 4: Now go to the extracted folder in Step 1 and open up the SP Flash Tool sub-folder. You will find “Flash_tool.exe” file in it. Launch it.

Step 5: Once SP Flash tool is launched, click on “Download” tab.

Step 6: Now, click on “scatter-loading” button in the download tab.

Step 7: Next, click on “Open Scatter File” and select the scatter file from Step 1. For reference see the image given below.

Step 8: Now click on the “Download” button to start the flashing process.

Step 9: Now, Connect Your Smartphone to the computer using USB Cable (without battery-if it is removable). After connecting the device to the computer press Volume Down Or Volume UP key, so that your computer easily detect your smartphone

Step 10: The flashing process will begin momentarily, and it will get completed in a minute or two. Once it is over, you will see the “Download OK” green ring in SP Flash Tool.

Step 11: Now, close SP Flash tool on your computer and unplug your smartphone.