The latest android update can be downloaded Over The Air (OTA) from the manufacturers which does not need rooting in the process. Not all Android devices have updates but you can install HTC Desire 516 Custom Rom unofficially to upgrade you mobile to the latest version. This method requires you to root the device which will break your mobile’s warranty. These custom ROMs are developed by some developers in an online community that build their own ROMs by making some changes in stock ROM. They can get all the source code for free since Android is an open source software.
Custom Rom Preparations
There are lots of sources out there that offer their own custom ROM for your device but make sure you choose the HTC Desire 516 Custom Rom that can be trusted. Installing a bad ROM may cause damage or even brick your phone. If you have found the right one, the zip file should contain zdsrooter tool, boot.img file, and adb run. Then, you need to download and install SDK manager on your phone and the drivers for your phone on the computer. Now open ADB RUN. Copy the boot.img file you have extracted from the root.zip file into C:drive\adb\img\boot folder.
Custom Rom Installation
Turn off your device and then press volume up and power button at the same time to enter recovery mode. Choose reboot bootloader from the menu or type adb reboot bootloader and then press enter in the command prompt. When your device stuck at HTC screen logo, you need to connect your USB cable. Once you connect the cable, start ADB RUN, type 5 key to enter FASTBOOT and then boot. Now press 2 key and then press any key to continue. You will be prompted to confirm the location of the boot.img file. Press any key to start the process. Once the process is complete, reboot your phone.
Now install and run zdsrooter tool. Press the green button when you see a popup appearing. Choose root option and then the King User app will appear on your device. Reboot device once again. You may also use supersu instead of king user. Next, you have to install su binary and then tap continue and then choose normal. If it fails to continue, you need to reboot your device. Now try installing su binary once again. It should not fail anymore. Now you have successfully installed HTC Desire 516 Custom Rom.